Voyage Planning Regulations
Master the IMO four-phase voyage planning framework, chart selection, weather routing, fuel planning, watch systems, and USCG requirements for offshore operations. Essential knowledge for the OUPV and Master captain's license exam.
Topics on This Page
1. IMO Voyage Planning — The Four Phases
The International Maritime Organization (IMO) Resolution A.893(21) establishes guidelines for voyage planning that apply to all commercial vessels. The framework divides every passage into four sequential phases. Exam questions frequently test your ability to categorize specific planning actions into the correct phase.
Gather all information relevant to the proposed voyage
- ✓Obtain and inspect all charts for the route — current editions, corrections up to date
- ✓Consult Sailing Directions, Coast Pilot, and Light Lists for the area
- ✓Review NOTAM and NOTMAR for any temporary changes to aids or hazards
- ✓Assess crew experience, certification, and watch-standing capability
- ✓Check vessel seaworthiness: machinery, safety gear, fuel capacity, stability
- ✓Research weather patterns for the season and the passage duration
- ✓Identify all ports of refuge, divert anchorages, and emergency contacts en route
- ✓Determine pilot requirements, customs/immigration procedures at ports of call
Develop the detailed, written passage plan
- ✓Lay down the planned track with waypoints, courses, and distances
- ✓Plot all no-go areas and identify danger bearings and clearing lines
- ✓Establish safety margins: minimum depth contours, off-track limits
- ✓Compute tidal gates and determine valid departure windows
- ✓Calculate fuel requirements including reserve; identify bunkering ports
- ✓Plan watch schedule in compliance with STCW rest requirements
- ✓Prepare communications plan: VHF channels, SSB schedules, check-in times
- ✓Brief all crew on the plan, emergency stations, and individual responsibilities
- ✓Leave float plan with a reliable contact ashore
Carry out the plan with continuous situational awareness
- ✓Depart within the planned weather and tidal window
- ✓Monitor vessel position against the planned track at regular intervals
- ✓Update weather information continuously; reassess routing decisions
- ✓Maintain proper watch — dedicated lookout, helmsman, and navigator functions
- ✓Log position, course, speed, and significant events every hour or at watch change
- ✓Make scheduled radio check-ins per the communications plan
- ✓Fuel monitoring: log consumption vs. planned; flag any divergence early
- ✓Immediately inform master of any deviation from the passage plan
Continuously compare actuals to the plan and adapt
- ✓Cross-check position using multiple methods: GPS, radar, visual, depth
- ✓Compare actual speed made good against planned — adjust ETA accordingly
- ✓Monitor fuel consumption closely; recalculate range in adverse conditions
- ✓Continuously reassess weather against the route; be prepared to divert
- ✓Track crew rest hours — ensure no STCW violations accumulate
- ✓Update port entry estimates and contact ahead when schedule changes
- ✓Document all significant deviations and decisions in the log
- ✓Conduct post-voyage review: what worked, what needs updating for next time
Exam tip: The IMO phases are sequential and iterative — you return to monitoring throughout the passage and may replan if conditions change significantly. The OUPV exam may ask which phase a specific action belongs to. Appraisal = gathering information. Planning = deciding route and resources. Execution = underway. Monitoring = continuous comparison of actuals to plan.
2. Chart Selection
Selecting the correct chart for each phase of navigation is a fundamental skipper responsibility. The wrong chart scale — too small for pilotage, too large for passage — creates navigational hazards. NOAA publishes both paper charts and free digital downloads; corrections must be applied to maintain legal and safe status.
Chart Scale Selection
| Scale | Chart Type | Best Use |
|---|---|---|
| 1:1,200,000 and smaller | Sailing charts | Ocean passage planning; broad overview of routing options |
| 1:150,000 – 1:600,000 | General charts | Coastal navigation along stretches of coastline |
| 1:50,000 – 1:150,000 | Coastal charts | Navigating along the coast with more detail |
| 1:25,000 – 1:50,000 | Approach charts | Approaching a port or harbor entrance |
| 1:5,000 – 1:25,000 | Harbour/berthing plans | Entering and maneuvering within a harbor or marina |
Chart Corrections and Currency
Notice to Mariners (NtM)
Published weekly by the USCG and NGA. Contains chart corrections, new editions, NOTMAR changes to aids to navigation, and temporary changes. Chart corrections must be applied in permanent ink or pencil. Each correction cites the chart number, edition date, and correction number.
Local Notice to Mariners (LNtM)
Published weekly by each USCG District. Contains corrections to charts of local importance: buoy repositioning, dredging changes, temporary shoaling, and local hazards. Required reading for any skipper operating regularly in a district.
NOAA Chart Updates
NOAA updates its free downloadable charts on a rolling basis. Dates of issue are printed on the chart. When printing or downloading, record the edition date. For critical pilotage, always download the most recent edition before departure.
ENC vs. RNC
An ENC (Electronic Navigational Chart) is a vector database used in ECDIS systems; it enables automatic safety checking, alarm zones, and route analysis. An RNC (Raster Navigational Chart) is a digital scan of a paper chart used in chartplotters. ENCs are the higher regulatory standard and the future of digital navigation.
Key Chart Features for Route Planning
3. Route Planning
A written passage plan is required for all commercial voyages and is best practice for any offshore passage. The route plan translates the appraisal information into a specific track, waypoints, and safety parameters that watchkeepers can follow and measure against.
Waypoints
- ·Position waypoints at course changes, tidal gates, and significant hazard passing points
- ·Number waypoints sequentially; record in a waypoint log separate from the chartplotter
- ·Cross-check chartplotter waypoints against the paper chart before departure
- ·Use parallel index techniques near hazards — do not rely solely on GPS
- ·Record the waypoint coordinates in the passage plan log for manual backup
Safety Margins
- ·Define a maximum off-track limit in the plan — typically 0.5 to 1.0 NM offshore
- ·Plot minimum safe depth contours and treat them as hard limits
- ·Set radar range rings and ECDIS safety depth alarms before departure
- ·Use parallel index lines on radar to maintain clearance from hazards
- ·Establish abort criteria: conditions under which you divert, anchor, or return
No-Go Areas
- ·Identify and mark all areas that must never be entered: shoals, restricted zones, submarine cables
- ·Apply a safety buffer of at least the vessel's beam plus tide uncertainty around each hazard
- ·Note charted positions may have survey uncertainty — older charts have larger position errors
- ·Highlight no-go areas in red on the chart or paper printout
- ·Brief all watchkeepers on no-go areas before departure
Danger Bearings and Clearing Lines
Danger Bearing
A danger bearing is the limiting bearing to a landmark beyond which a vessel enters unsafe water. Plotted on the chart and continuously monitored while passing the hazard area.
Example: "NMT (not more than) 047°T to Pt. Reyes Light while approaching the bar."
Clearing Line / Clearing Bearing
A range or bearing that, when maintained, keeps the vessel clear of a hazard. Often combined with a depth contour: stay in water deeper than 30 feet while maintaining a bearing of 185°T to the steeple.
Best practice: use two crossing clearing lines to create a defined safe corridor.
Track Lines
The planned track is drawn as a solid line on the chart. A parallel dashed line offset by the off-track tolerance defines the exclusion zone. Watchkeepers must immediately notify the officer of the watch if the vessel reaches the dashed limit.
Wheel-Over Points
The point at which the helm must be put over to complete a course change before reaching the next waypoint. Calculated based on vessel turning circle and speed. At 10 knots, a vessel may advance 0.5 NM in a significant turn — the wheel-over point must be plotted ahead of the waypoint.
4. Weather Routing
Weather is the single greatest variable in offshore passage planning. A skipper who reads weather well and routes around heavy conditions arrives safely and on time. A skipper who ignores weather or misreads forecasts risks vessel and crew. The exam tests basic weather knowledge as well as familiarity with routing tools.
Synoptic Analysis
Reviewing surface analysis and forecast charts from NOAA/NWS to understand the big picture pressure systems, fronts, and general wind flow for the passage.
Sources: NOAA Weather Service, Ocean Prediction Center, passageweather.com
GRIB Files
Gridded Binary format weather model output downloaded to a chartplotter or navigation software. Provides wind speed/direction, wave height, and sometimes current overlaid directly on the chart.
Sources: NOAA GFS/NAM models, ECMWF (European model), PredictWind, Expedition
Commercial Routing Services
Professional meteorologists who review vessel parameters and voyage plan, then issue custom routing recommendations with updates throughout the passage.
Sources: Commanders Weather, World Weather & Navigation, Buoyweather Pro
Voluntary Observing Ships (VOS)
Actual weather observations from commercial vessels at sea, compiled into products that supplement model data for offshore passages.
Sources: NOAA VOS program; Coast Guard Broadcast Notice to Mariners
SSB/Weatherfax
High Frequency (HF) radio broadcasts of weather charts and text forecasts; satellite-quality charts available without internet at sea.
Sources: NMN (Chesapeake), NMF (San Francisco), KVM70 (Honolulu) — USCG stations
Heavy Weather Avoidance Rules
- ⚠Never depart into an already-existing gale forecast if avoidable
- ⚠A backing wind (counterclockwise shift) often signals an approaching warm front
- ⚠A veering wind (clockwise shift) may indicate a cold front passage or Northern Hemisphere high approach
- ⚠Barometric pressure dropping more than 0.10 inches/Hg per hour signals rapid deterioration
- ⚠Stay to the navigable semicircle of a tropical system — never transit the dangerous semicircle
- ⚠In the Northern Hemisphere: the dangerous semicircle is to the right of the storm track
- ⚠If caught out: heave to or run off; do not continue pounding into head seas
Weather Broadcast Schedule Reference
5. Tidal Gates and Current Planning
Tidal gates and current planning are among the most operationally critical elements of coastal passage planning. Missing a tidal gate can add many hours to a passage, force an overnight anchorage in an unplanned location, or create a genuine safety hazard on an exposed bar or inlet.
Tidal Gate Planning Process
- 1Identify all tidal gates on the route: bars, inlets, shallows, bridges with fixed vertical clearance
- 2Obtain the current year's NOAA tide tables for the stations nearest each gate
- 3Determine the minimum safe depth needed: vessel draft + safety margin (minimum 1 foot, preferably more)
- 4Calculate water depth at each gate: chart datum depth (MLLW) + tidal height at transit time
- 5Identify all transit windows where calculated depth exceeds minimum safe depth
- 6Work backwards from gate windows to determine required departure time
- 7If two gates are in series, find the departure window satisfying both simultaneously
- 8Build in buffer: arrive at the gate 15-30 minutes before the window opens, not at its close
Rule of Twelfths
The Rule of Twelfths is a quick mental model for estimating the tidal height at any time between high and low water (assuming a semi-diurnal tide with a regular sine curve):
Total must equal 12/12 of the tidal range. Use this to estimate height between known high and low water times without interpolating tables.
Current Planning — Optimal Departure Timing
Favorable Current
A 1-knot favorable current adds 1 NM per hour to effective range and reduces fuel consumption. On a 200 NM passage this equates to 20 hours saved at 10 knots — plan to ride fair current.
Opposing Current
A 2-knot adverse current against a 7-knot vessel effectively reduces speed over ground to 5 knots — adding 40% to passage time and fuel. Time passages to minimize adverse current in narrows.
Slack Water
Many inlets and narrows are only safe during the brief slack period between flood and ebb. Consult the Current Tables (not the Tide Tables) — slack water can occur up to 3 hours after high or low tide.
6. Fuel Planning
Running out of fuel offshore is a preventable emergency. Proper fuel planning uses the 1/3-1/3-1/3 rule as a minimum standard, supplemented by careful calculations based on the vessel's actual consumption rate, planned speed, and conditions.
Outbound 1/3
Fuel for the outbound leg at planned cruising speed
Calculate based on engine burn rate (GPH) times estimated leg time
Return 1/3
Fuel for the return leg — never count on bunkering at destination
Plan as if fuel is unavailable at the destination; always have enough to return
Reserve 1/3
Emergency reserve — never plan to use this for normal operations
Covers adverse weather, increased headwind, diversions, mechanical issues
Fuel Calculation Method
Step 1 — Determine burn rate
Know your vessel's actual GPH at cruising RPM. Run the engine at cruise for one hour with a known starting fuel level and measure consumption. Never rely on manufacturer specs alone — actual consumption depends on hull condition, loading, and sea state.
Step 2 — Calculate passage fuel
Passage fuel = distance (NM) / speed (knots) x burn rate (GPH). Add 10-15% for adverse conditions, headwinds, and current — sea conditions routinely increase fuel burn significantly over flat-water estimates.
Step 3 — Apply the reserve
Reserve must be equal to the larger of: 1/3 of total fuel planned OR a fixed number of hours at cruise (often 4-6 hours minimum for offshore). Some commercial operators specify a percentage of tank capacity as a hard minimum floor.
Step 4 — Identify bunkering ports
For long passages, identify intermediate bunkering ports. Confirm fuel availability in advance — not all marinas carry diesel. Know the hours of operation and whether advance notice is required for large deliveries.
Exam note: The 1/3-1/3-1/3 rule is a minimum standard, not an engineering calculation. For the exam, know how to apply it: total fuel divided by 3 equals the reserve, which also equals the one-way leg allowance. If the question gives you a one-way leg fuel requirement and asks for total fuel, multiply by 3. If it gives total fuel and asks for the reserve, divide by 3.
7. Communications Plan
A communications plan defines which radio systems will be used, when scheduled contacts occur, what information will be passed, and who the shore contact is. A pre-departure communications brief is essential for any offshore passage.
| Medium | Primary Purpose | Key Notes |
|---|---|---|
| VHF Channel 16 | Distress, safety, and calling channel — monitor at all times underway | All commercial vessels required to maintain continuous watch |
| VHF Channel 22A | Primary USCG working channel in U.S. waters | Switch from 16 to 22A when contacted by USCG |
| DSC (Digital Selective Calling) | Automated distress alert transmitting MMSI and position to GMDSS network | MMSI must be registered with USCG or BoatUS/Sea Tow |
| SSB / MF-HF Radio | Long-range voice and digital comms beyond VHF range (offshore) | Required for GMDSS Area A2, A3, A4 voyages |
| Satellite Phone (Iridium/Inmarsat) | Global voice and data regardless of location; primary offshore comms backup | Also used for receiving weather GRIB files |
| EPIRB (406 MHz) | Automatic or manual distress beacon; transmits to COSPAS-SARSAT system | Must be registered with NOAA; replace hydrostatic release every 2 years |
| PLB (Personal Locator Beacon) | Personal-use distress beacon; same satellite system as EPIRB but not auto-activated | Worn by individual; excellent for MOB insurance |
| Inmarsat-C / Fleet One | Two-way text messaging and safety data worldwide; can receive SafetyNET weather | Used for commercial passage check-ins and safety messages |
Float Plan Elements
- •Vessel name, type, size, color, registration/documentation number
- •Engine type, horsepower, number of engines
- •Names, ages, and emergency contacts for all persons aboard
- •Complete itinerary: departure point, all stops, destination
- •Planned departure time and expected arrival time
- •Safety equipment: EPIRB MMSI/HEX ID, life raft, flare kit
- •Radio frequencies monitored and scheduled check-in times
- •Name and phone number of shore contact; instructions if overdue
Check-in Schedule
For offshore passages, establish a fixed check-in schedule with the shore contact. A common format:
8. Watch System Planning and STCW
Fatigue is one of the leading contributing factors in maritime casualties. STCW (Standards of Training, Certification and Watchkeeping) establishes mandatory minimum rest periods for commercial mariners. Understanding these requirements — and designing a watch schedule that meets them — is an essential skill for any licensed master.
| STCW Requirement | Minimum | Notes |
|---|---|---|
| Minimum rest in any 24-hour period | 10 hours | May be split into 2 periods; one must be at least 6 consecutive hours |
| Minimum rest in any 7-day period | 77 hours | 168 hours in a week minus 91 hours maximum work = 77 minimum rest |
| Maximum number of rest divisions | 2 per 24 hours | Rest cannot be split into more than 2 segments per day |
| Minimum length of one rest period | 6 consecutive hours | One of the two daily rest periods must be at least 6 uninterrupted hours |
| Exception for emergency/drills | Compensatory rest | Rest hours missed for emergency or drill must be made up as soon as practicable |
4-on / 8-off (Traditional)
3+ officersOfficer stands 4-hour watches; 8 hours off. Classic merchant arrangement. Provides full compliance with STCW minimum rest standards.
Best for: Large vessel with large crew
6-on / 6-off
2 officersTwo officers alternate 6-hour watches. Technically STCW-compliant if rest periods are protected, but fatiguing on long passages.
Best for: Smaller vessel, short passages
Swedish Watch (3-watch, rotating)
3 officersWatch rotates through 4-hour, 4-hour, and 8-hour shifts on a repeating cycle so each watchstander cycles through all times of day over 3 days.
Best for: Offshore passages; reduces circadian disruption
Watch-and-watch (50/50)
2 personsCommon on recreational offshore boats. 4 hours on, 4 hours off, continuously. STCW non-compliant for commercial vessels but widely used recreationally.
Best for: Short-handed recreational passages
Single-hander approach
1 personNo watch system is STCW-compliant for one person. Best practice: 20-minute naps in calm conditions, radar alarm, AIS target alarm, drift alarm on autopilot. Extremely high risk offshore.
Best for: Recreational only; not STCW-compliant
9. Port Entry Planning
Arriving at a new port — especially a foreign port — requires extensive advance research. Failures in port entry planning can result in regulatory violations, vessel detention, fines, or serious safety hazards when attempting to enter an unfamiliar harbor without a plan.
Pilotage Requirements
- ✓Research whether pilotage is compulsory for your vessel at the destination port
- ✓Commercial vessels over 300 GRT typically require a licensed pilot in major U.S. ports
- ✓Recreational vessels and small commercial vessels are usually exempt but confirm locally
- ✓Contact the port authority or agent well in advance to arrange a pilot if required
- ✓Have the vessel draft, LOA, beam, and advance notice of arrival (NOA) ready
Customs and Immigration
- ✓Arriving from a foreign port: crew and passengers must clear U.S. Customs and Border Protection
- ✓File advance notice of arrival electronically via eNOA/D system minimum 96 hours prior
- ✓Fly the yellow quarantine flag (Q flag) until cleared by CBP
- ✓Crew must have valid passports; NEXUS or CBP ROAM app may streamline clearance
- ✓No one goes ashore until cleared — even to get fuel or supplies
Port State Control
- ✓Port State Control (PSC) officers may board and inspect any commercial vessel in their waters
- ✓PSC inspections cover certificates, safety equipment, crew certification, ISM compliance
- ✓Deficiencies can result in detaining the vessel until corrected
- ✓U.S. PSC is conducted by the USCG; Paris MOU, Tokyo MOU in other regions
- ✓Vessels with poor port state histories are targeted for increased inspection frequency
Notice of Arrival (NOA)
- ✓Required for all vessels 300 GT or more arriving from foreign ports, or carrying certain cargo
- ✓Submit via CBP eNOA/D: vessel info, crew list, cargo manifest, arrival details
- ✓Vessels that did not clear customs abroad must report immediately upon arrival
- ✓Failure to comply results in significant fines and vessel detention
Port Entry Checklist — Offshore Arrival
10. Safety Brief and Crew Assignments
A pre-departure safety brief is required on all commercial vessels carrying passengers and is best practice on any offshore voyage. The brief ensures every person aboard knows what to do in an emergency before the emergency occurs — not during it.
Emergency Stations
- •Muster station location and assembly signal
- •Life raft location, launching procedure, and painter attachment
- •Life jacket location, donning method, and size selection
- •EPIRB location and activation procedure
Abandon Ship
- •Alarm signal: prolonged blasts of horn plus word of command
- •Grab-bag contents and who is responsible for it
- •Life raft boarding sequence: most vulnerable persons first
- •Maintaining contact with the vessel if conditions permit
Fire Party
- •Location of all fire extinguishers aboard
- •Type of extinguisher for each space: B for fuel fires, water for Class A
- •Engine room fire protocol: close vents, activate fixed system, do not open door
- •Fire reporting chain: who calls MAYDAY, who fights, who mans helm
Man Overboard
- •Immediate actions: shout MOB, point at person, press MOB button
- •Helm responsibilities: immediate turn back
- •Recovery equipment location: throw ring, dan buoy, boarding ladder
- •Recovery procedure and who swims if necessary
Crew Assignments
- •Watch schedule: who has helm, lookout, and navigation responsibilities
- •Cooking and meal schedule to prevent galley fires from unattended stoves
- •Designated person responsible for daily position log
- •Radio watch: who monitors VHF 16 when off watch
Safety Equipment Location
- •First aid kit location and who has medical training
- •Flare kit location and expiration dates — pre-brief on types and use
- •Jacklines, harnesses, and tether attachment points for offshore work
- •Lifebuoy with self-igniting light location on stern rail
11. USCG Requirements for Offshore Operations
Commercial vessels operating offshore are subject to USCG inspection and enforcement. The following table summarizes key equipment requirements for uninspected commercial vessels on offshore passages. Always verify against current CFR requirements as regulations change.
| Equipment Item | Requirement | Regulatory Reference |
|---|---|---|
| Float Plan | Not legally required but strongly recommended for all offshore trips | USCG boating safety guidance |
| PFDs | One USCG-approved Type I, II, III, or V per person; Type I offshore | 46 CFR 25.25 |
| Flares / Visual Distress Signals | Required on federal waters between sunset and sunrise; recommended offshore at all times. Minimum: 3 day, 3 night or combination | 33 CFR 175.130 |
| EPIRB | Required on uninspected commercial vessels on high seas voyages; Category I EPIRB for auto-deployment | 47 CFR 80; 46 CFR 25.26 |
| Fire Extinguishers | Minimum one B-I per engine compartment; more based on vessel length and configuration | 46 CFR 25.30 |
| Navigation Lights | Must display proper lights between sunset and sunrise per ColRegs or Inland Rules | 33 CFR 83 |
| Sound-Producing Device | Whistle required for vessels over 12m; bell and whistle for vessels over 20m | 33 CFR 86 |
| Anchor and Line | Sufficient anchor and line for vessel and area of operation; required for charter vessels | 46 CFR 28.305 |
| Bilge Pump | Manual bilge pump required for uninspected vessels on offshore passages | 46 CFR 25.40 |
| First Aid Kit | Required on inspected vessels; strongly recommended for all offshore operations | 46 CFR 160.041 |
USCG Vessel Examination
The USCG Auxiliary offers free vessel safety checks (VSC) that review equipment compliance. While not legally required, a current VSC decal indicates a vessel meets USCG safety standards. Commercial vessels are subject to boarding and inspection by active-duty USCG officers at any time.
- ✓Maintain all required certificates aboard: documentation, operator license, radio license
- ✓Safety equipment must be within service dates: extinguishers, EPIRBs, life rafts
- ✓Crew certification documents must be current and carried aboard
- ✓COI (Certificate of Inspection) for inspected vessels must be posted
MARPOL Compliance Offshore
MARPOL Annex V governs garbage disposal at sea. Key rules for offshore passage:
- •No plastic overboard — ever, anywhere
- •Food waste: may be discharged beyond 12 NM from land (outside special areas)
- •Paper and cardboard: comminuted or ground, beyond 3 NM (outside special areas)
- •Maintain a Garbage Management Plan for vessels 100 GT or more
- •Garbage Record Book required for vessels 400 GT or more carrying 15+ persons
- •U.S. special areas include Great Lakes, Gulf of Mexico — stricter rules apply
12. Emergency Contingency Planning
The passage plan must include contingency plans for foreseeable emergencies. The goal is to make decisions before they are needed, under stress, in bad conditions. A skipper who has pre-planned the response to a MOB or fire can act immediately — one who has not will lose critical time.
Assign spotter, execute MOB maneuver (Williamson turn offshore), activate DSC, deploy dan buoy, assign swimmer/recovery team, log time and position
Sound alarm, send MAYDAY if fire uncontrolled, don lifejackets, muster at abandon-ship station, fight fire at source with correct extinguisher type, isolate fuel/electrics
Locate source, activate bilge pumps, deploy damage control plugs, sound MAYDAY with position and souls aboard, prepare life raft and abandon-ship bag
Activate EMS communication via Coast Guard or Rescue Coordination Center, contact COGARD medical advisory, prepare for MEDEVAC rendezvous or helicopter hoist
Assess whether vessel can continue under jury rig or auxiliary power, notify nearest port authority, request tow if necessary, activate EPIRB if vessel not under command
Switch to backup chartplotter or tablet, revert to manual DR navigation, take visual bearings, use radar for overlay, contact nearest vessel for positional assistance
Implement heavy weather watch schedule, reduce sail/speed, alter course if necessary, monitor barometer trend, update routing, prepare crew with harnesses and tethers
Divert Port Planning
For every significant leg of a passage, identify divert ports — sheltered anchorages or marinas where you can take refuge if conditions deteriorate or an emergency arises. Pre-plan:
- •The VHF channel for the port or marina
- •Approach depths and any tidal restrictions
- •Fuel availability and hours
- •Distance and bearing from the planned track
- •Customs requirements if crossing a border to divert
Medical Evacuation (MEDEVAC) Plan
Medical emergencies at sea require a pre-planned response:
- •Maintain a current first aid kit and have at least one trained person aboard
- •USCG can provide medical advice on VHF 16 or via 1-800-323-7233 (COGARD)
- •For serious injuries, declare URGENCY (PAN PAN) or MAYDAY and request MEDEVAC
- •Know your position, nearest port, helicopter landing area on the vessel
- •Have the patient's medical history available to relay to the RCC
- •Clear the deck for helicopter hoist operations if required
13. Practice Problems with Solutions
Work through each problem before expanding the solution. These represent the type of applied calculation and judgment questions that appear on the OUPV and Master exams.
1You are planning a 220 NM offshore passage. Your vessel burns 8 gallons per hour at 10 knots. How many gallons of fuel must you have aboard at departure, applying the 1/3-1/3-1/3 rule, and what is the minimum tank capacity needed?
Solution
Step 1 — Calculate passage time: 220 NM at 10 knots = 22 hours Step 2 — Calculate fuel needed for one leg: 22 hours x 8 GPH = 176 gallons Step 3 — Apply the 1/3-1/3-1/3 rule: the 176 gallons represents 2/3 of total fuel (outbound + return legs) Step 4 — Total fuel required: 176 gallons / (2/3) = 264 gallons total Step 5 — Reserve portion: 264 gallons x (1/3) = 88 gallons reserve Step 6 — Answer: You need 264 gallons aboard at departure. Your tank must hold at least 264 gallons. Note: This is a one-way passage, so outbound 1/3 = 88 gal, return 1/3 = 88 gal, reserve 1/3 = 88 gal. Many exam problems ask for the total or just the reserve — be sure to read carefully.
2Your watch officer calls you to the bridge. The vessel's position on the chartplotter shows you are 0.8 NM north of the planned track. The nearest charted shoal is 1.1 NM to the north of your current position. What are your immediate actions and what factors determine whether to correct back to track?
Solution
Immediate actions: 1. Verify the position using a second method: radar fix, visual bearing, or depth sounder vs. charted depths 2. Confirm the chart is corrected to the latest edition and any local NOTMARs are accounted for 3. Plot the current position and the shoal with clearance margin on the chart Decision factors: - Safety margin remaining: 1.1 NM - 0.8 NM off-track = 0.3 NM clearance remaining — this is MARGINAL - Standard offshore safety margin is typically 0.5-1.0 NM from charted hazards - With only 0.3 NM remaining, correcting back toward track is prudent - Consider: is the shoal position confirmed on a recent chart? Is there a depth alarm set? Corrective action: Alter course toward the planned track, inform the master, log the event, and reassess the routing to ensure the planned track provides adequate clearance for future legs.
3You are planning a coastal passage that requires transiting a tidal bar with a minimum depth of 7 feet at MLLW. Your vessel draws 5.5 feet. The tide tables show a high tide of 3.2 feet above MLLW at 0840 and 0.6 feet at 1454. What is the earliest safe transit window and the effective clearance at that time?
Solution
Step 1 — Determine depth needed: vessel draft 5.5 ft + safety margin (typically 1 ft minimum) = 6.5 ft minimum depth Step 2 — Bar depth at high water: 7 ft (MLLW) + 3.2 ft (high tide height) = 10.2 ft Step 3 — Clearance at high tide: 10.2 ft - 5.5 ft draft = 4.7 ft clearance — more than adequate Step 4 — Determine safe window: Need 6.5 ft minimum total depth. Available depth = 7 + tide height. Set 7 + tide height >= 6.5, so tide height >= -0.5 ft — effectively any time tide is above -0.5 MLLW Step 5 — With a high of 3.2 ft at 0840, there is generous time before the bar becomes critical Step 6 — Use the Rule of Twelfths to estimate the tide curve if needed: - Hours 1 and 6: 1/12 of tidal range change per hour - Hours 2 and 5: 2/12 per hour - Hours 3 and 4: 3/12 per hour Best transit: Within 2-3 hours of the 0840 high tide, from approximately 0630 to 1100, depending on the full tidal curve analysis.
4You are the skipper of a 50-foot motor vessel operating as a USCG-licensed charter boat offshore. List five required items of safety equipment and state the regulatory reference for each.
Solution
Required items for offshore charter operations: 1. Personal Flotation Devices — One USCG-approved PFD per person aboard; Type I (offshore) strongly recommended. Ref: 46 CFR 25.25-1 2. Visual Distress Signals (VDS) — Night signals (flares), day signals, or combination approved devices; minimum 3 day and 3 night devices. Ref: 33 CFR 175.130 3. Fire Extinguishers — At minimum one Type B-I extinguisher per enclosed engine compartment; more based on vessel length. Ref: 46 CFR 25.30 4. Sound-Producing Device — A whistle audible at 0.5 NM; vessels over 20m also require a bell. Ref: 33 CFR 86.01 5. Navigation Lights — Proper lights for the vessel type and operation, operational between sunset and sunrise and in restricted visibility. Ref: 33 CFR 83 (Inland) / 72 COLREGS (International) Additional requirement for offshore charter: EPIRB (Category I, 406 MHz) is required for uninspected commercial vessels on high seas voyages. Ref: 47 CFR Part 80 and 46 CFR 25.26
5During the appraisal phase of your passage plan, you discover there is a NOTMAR indicating a light has been changed to a temporary buoy while the lighthouse is under repair. The published chart still shows the lighthouse. What specific actions do you take?
Solution
Actions required when a NOTMAR conflicts with the published chart: 1. Annotate the chart: Using pencil, note the NOTMAR number, date, and nature of the change directly on the chart at the affected location 2. Record the correction: Log the NOTMAR reference in the chart's correction record (typically inside the chart or in a corrections log) 3. Update the ENC/chartplotter if applicable: If using electronic charts, check whether the NOTMAR has been incorporated into the latest ENC update; if not, add a user waypoint or note in the chartplotter 4. Adjust the passage plan: If the change affects your planned approach route — such as the lighthouse being a critical landfall mark or a reference for a danger bearing — revise the waypoints and bearings accordingly 5. Brief the watch officer: Ensure all officers on watch are aware of the change and know not to rely on the published light characteristic 6. Monitor during transit: Cross-check position against the actual temporary buoy location, not the charted lighthouse position This process reflects the broader principle that a chart is only as good as its latest correction — always use Notice to Mariners to keep charts current.
Frequently Asked Questions
What are the four IMO voyage planning phases?+
The IMO requires all voyages to be planned in four phases: (1) Appraisal — gathering all relevant information about the voyage including charts, weather, tides, hazards, port entry requirements, and crew capabilities; (2) Planning — laying out the detailed route with waypoints, track lines, safety margins, no-go areas, and contingency plans; (3) Execution — carrying out the plan with proper watch standing, position monitoring, and updating as conditions change; (4) Monitoring — continuously comparing actual position and conditions against the plan and adjusting as necessary. This framework applies to all commercial vessels and is tested on the OUPV and Master exams.
What is the 1/3 rule for fuel planning?+
The 1/3-1/3-1/3 fuel rule divides usable fuel into three equal portions: 1/3 for the outbound leg, 1/3 for the return leg, and 1/3 as reserve. The reserve should never be planned for normal use. Some operators apply a stricter formula for offshore operations: calculate fuel needed for the passage at cruising speed, add 10% for increased consumption in adverse conditions, and add a fixed reserve (often 10-15% of tank capacity or a minimum number of hours at cruise). USCG regulations require sufficient fuel for the intended voyage plus reserve.
What STCW rest requirements apply to watch standing?+
STCW (Standards of Training, Certification and Watchkeeping) requires a minimum of 10 hours of rest in any 24-hour period and 77 hours of rest in any 7-day period. Rest periods may be divided into no more than two periods, one of which must be at least 6 hours. These requirements apply to all commercial mariners subject to STCW conventions. For offshore passage planning, voyage planners must design watch schedules that comply with these minimums. Single-handers on recreational vessels are not subject to STCW, but fatigue management is a critical safety consideration regardless.
What is the difference between ENC and RNC charts?+
An ENC (Electronic Navigational Chart) is a vector-format chart database conforming to IHO S-57 standards, used in an ECDIS (Electronic Chart Display and Information System). ENCs allow automatic alarm functions, route checking against chart data, and dynamic information layers. An RNC (Raster Navigational Chart) is a digital scan of a traditional paper chart — essentially a high-resolution image. RNCs look identical to paper charts and are used in many chartplotters, but they do not support the automatic safety checking features of ENCs. USCG regulations allow either for SOLAS vessels, but ECDIS with ENCs is the higher standard.
What are tidal gates and why do they matter for voyage planning?+
A tidal gate is a location where the state of the tide or tidal current critically affects whether a vessel can safely pass — either due to depth over a shoal or bar, or due to current strength in a narrows or inlet. Proper tidal gate planning requires identifying all gates on the route, computing the earliest and latest safe transit windows for each gate, and working backwards from those windows to determine the required departure time. Missing a tidal gate can mean waiting 6 or 12 hours for the next safe window, or being forced to anchor in an unsafe location.
What must a USCG float plan include?+
A float plan is not legally required by the USCG but is strongly recommended for all offshore voyages. A complete float plan should include: vessel name, type, registration/documentation number, hull and sail description, engine type and horsepower, fuel capacity; persons aboard with names, ages, addresses, and emergency contacts; complete trip itinerary including departure point, waypoints, destination, and expected return time; safety equipment aboard including EPIRBs, flares, and life raft description; radio frequencies monitored; and contact information for who to notify if overdue. The float plan should be left with a responsible person ashore, not filed with any agency.
What is a danger bearing and how is it used in route planning?+
A danger bearing is the maximum (or minimum) bearing to a known landmark that keeps a vessel in safe water — beyond that bearing lies a hazard. For example, if rocks lie to the west of a headland, a navigator might determine that a bearing of no more than 285 degrees to the lighthouse keeps the vessel clear. This bearing is plotted on the chart and monitored throughout the passage of that area. Danger bearings are combined with clearing ranges and depth contour lines to create a safety corridor. They are particularly valuable in coastal pilotage when crossing between offshore and inshore waters.
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