Passage Planning – Essential Steps
A ship’s passage planning involves 4 major steps/stages. They are as follows:
Passage planning or voyage planning is a procedure to develop a complete description of a vessel’s voyage from start to finish. The plan includes leaving the dock and harbor area, the en route portion of a voyage, approaching the destination, and mooring, the industry term for this is ‘berth to berth’. According to international law, a vessel’s captain is legally responsible for passage planning.
Studies show that human error is a factor in 80 percent of navigational accidents and that in many cases the human making the error had access to information that could have prevented the accident. The practice of voyage planning has evolved from penciling lines on nautical charts to a process of risk management.
1 Planning stages
2 Computer aids
Monitoring progress and comparing it to the plan are key to passage planning.
Passage planning consists of four stages: appraisal, planning, execution, and monitoring.
These stages are specified in International Maritime Organization Resolution A.893(21), Guidelines For Voyage Planning, which are, in turn, reflected in the local laws of IMO signatory countries. The Guidelines specify fifty elements of passage planning, some of which are only applicable in certain situations.
Having and using a voyage plan is of essential importance for safety of life at sea, safety and efficiency of navigation and protection of the marine environment. Voyage planning is necessary for all types of vessels on all types of voyages, and the plan’s scope should be based on all information available, should be “berth to berth,” including when under pilotage, and the plan includes the execution and the monitoring of progress.
Voyage planning starts with the appraisal stage. Before each voyage begins, the navigator should develop a detailed mental model of how the entire voyage will proceed. The appraisal stage consists of gathering and contemplating all information relevant to the voyage. Much of this appraisal is done by consulting nautical charts, nautical publications and performing a number of technical tasks such as weather forecasting, prediction of tides and currents, and checks of local regulations and warnings.
Nautical publications are a valuable guide to local conditions and regulations, but they must be updated and actually read to be of any use. These publications could include Sailing Directions and Coast Pilots or similar texts produced by other authorities.
The next stage of the process is known as the planning stage. Once information is gathered and considered, the navigator can begin the process of actually laying out the voyage. The process involves projecting various future events including landfalls, narrow passages, and course changes expected during the voyage. This mental model becomes the standard by which the navigator measures progress toward the goal of a safe and efficient voyage, and it is manifested in a passage plan.
A good passage plan will include a track line laid out upon the best-scale charts available. This track is judged with respect to at least nine separate criteria given in Guidelines including under-keel clearance, safe speed, air draft, the use of routing and reporting services (TSS and VTS), and the availability of contingencies in case of emergency.
Modern navigators often enter passage plans on electronic systems.
In modern times, computer software can greatly simplify the passage planning process and ensure that nothing important is overlooked. Passage planning software may include functions such as waypoint management, distance calculators, tide and tidal current predictors, celestial navigational calculators, consumables estimators for fuel, oil, water, and stores, and other useful applications.
The navigator will draw and redraw the track line until it is safe, efficient, and in line with all applicable laws and regulations. When the track is finished, it is becoming common practice to also enter it into electronic navigation tools such as an Electronic Chart Display and Information System, a chartplotter, an ARPA system, or a GPS unit.
When working in a team environment, the passage plan should be communicated to the navigation team in a pre-voyage conference in order to ensure that all members of the team share the same mental model of the entire trip.
The third stage of passage planning is the execution stage. The IMO was careful to include execution as part of the process of passage planning. This underscores the fact that the Guidelines list a number of tasks that are to executed during the course of the voyage. It also reiterates the captain’s responsibility to treat the plan as a “living document” and to review or change it in case of any special circumstances that should arise.
The fourth and final stage of voyage planning is the monitoring stage. Once the voyage has begun the progress of the vessel along its planned route must be monitored. This requires that the ship’s position be determined, using standard methods including dead reckoning, celestial navigation, pilotage, and electronic navigation.
According to the Guidelines, the passage plan should always be available to the officer on watch on the bridge. The Guidelines also specify that deviations from the plan should be clearly recorded and be consistent with other provisions of the Guidelines.
Each stage in the passage planning has its own importance and it is extremely important to carry out each one of them with utmost care and up-to-date seamanship to ensure a safe sail.
In the start, a rough estimate is made of the whole sailing process. Once the rough plan is ready, it is further tweaked and modified/refined considering various details obtained from charts, pilot book, weather routing etc. These processes are carried out throughout the appraisal and planning stages.
In the next two stages i.e., execution and monitoring, the plan is used as a guideline, and the sailing is executed taking into consideration various factors, both observed and predicted.
Each aspect of passage planning has been explained in detail below:
In this stage, the master of the ship discusses with the chief navigating officer (usually the Second Mate), as to how he intends to sail to the destination port. (In some cases it may be required for the master to plan the passage). This is the process of gathering all information relevant to the proposed passage, including ascertaining risks and assessing its critical areas. This involves information extracted from publications as well as those within the chart. The appraisal will include details from:
- Chart Catalogue
- Ocean Passages of The World
- Routeing Charts
- Admiralty Sailing Directions
- Admiralty List of Lights and Fog Signals
- Admiralty List of Radio Signals
- Tide Tables
- Tidal Stream Atlas
- Notices to Mariners
- Admiralty Distance Tables
- Ships Routeing
- Navigational Warnings
- Mariner’s Handbook
- Load Line Chart
- Draft of Ship
- Owners and other sources
- Personal Experience
Taking into consideration master’s guidelines, company’s guidelines, ship’s cargo, marine environment, and all other factors that may affect the ship, the navigating officer draws upon a general track, which the ship shall follow.
For the ease of planning, this plan is first laid out on a small scale chart, which is later transferred to larger scale charts, and then minor modifications are made as and when deemed necessary.
Having made a full appraisal using all information at hand pertaining to the passage, the OOW, under the authority of the Master is to prepare a detailed plan for the passage. In this stage, the intended courses of the ships are actually laid out on the charts of suitable scale and all additional information is marked. The plan is laid out from pier to pier, including the pilotage waters.
It is a good practice to mark dangerous areas such as nearby wrecks, shallow water, reefs, small islands, emergency anchorage positions, and any other information that might aid safe navigation.
Reporting areas should also be clearly marked on the charts. Elements of the Planning phase include:
- No-Go areas
- Margins of safety
- Charted Tracks
- Course alterations and wheel over points
- Parallel Indexing
- Aborts and Contingencies
- Clearing line and bearings
- Leading lines
- Tides and current
- Change in engine status
- Minimum UKC
- Use of Echo Sounder
- Head Mark
- Natural Transit
Aborts: When approaching constrained waters, the vessel might be in a position beyond which there is no possible action but to proceed. For example, the vessel enters an area so narrow that there is no room to return. It is for this purpose that a position is drawn on the chart showing the last point wherein the passage can be aborted.
Contingencies: The bridge team must always be aware that the events might not go as planned and that emergency action might be required. Contingency plans account for such situations, clearly shown on the chart so that the OOW can take swift action in such a jam. Contingency planning will include alternative routes, safe anchorages, waiting areas, emergency berths.
In this stage, the navigating officers execute the plan that has been prepared. After departure, the speed is adjusted based on the ETA and the expected weather and oceanographic conditions. The speed should be adjusted such that the ship is not either too early or late at its port of destination. The Master should find out how long his intended voyage is, accounting for water and fuel available. Also to be taken into account are any expected weather changes along the way. In case and ECDIS is being used, appropriate limits must be set with regard to the safety settings.
Monitoring is that aspect which takes into account checking of the position of the vessel, such that it remains within the safe distance from any danger areas. Parallel Indexing can be used to maintain safe distance alongside any hazards to navigation. A safe and successful voyage can only be achieved by close and continuous monitoring of the ship’s progress along the pre-planned tracks. Situations may arise wherein the navigating officer might feel it prudent to deviate from the plan. In such case, he shall inform the master and take any action that he may deem necessary for the safety of the ship and its crew. This stage is a very important stage wherein all the deck officers contribute their part to execute the plan. This calls for personal judgement, good seamanship and experience.
The following are the factors that the Master must take into account when choosing an optimum route for an Ocean Passage :–
Type of vessel, draft and underkeel clearance at various stages of the voyage.
Time of the year and expected weather / sea conditions.
Available depths and width of water.
Possibility of encountering gale force winds causing subsequent delays or damage to the vessel.
Likelihood of encountering ice and fog causing delay or deviations from the planned route.
Predominant currents / tidal streams being either adverse or favourable to the ship’s course.
Economical route (fuel & time saving).
Good weather route (for passenger vessels).
Recommendations from Ocean Passages of the World.
Recommendations from Meteorological Office.
State of loading and nature / type of cargo.
Need of any tasks to be carried out during voyage.
Overall navigational aids on board.
Distances off from Islands and other navigational hazard, incase of engine failure.
War zones, fishing traffic, oil and gas offshore developments and abnormal waves.
Overall distance comparison
Company’s or charteres preference.
The following publications should to be consulted when making a passage plan:
- International Code of Signals (IMO)
- SAR Manual Vol
Mariners’ Handbook (UKHO)
- Merchant Shipping Notices
Marine Guidance Notes and Marine Information Notes (MCA)
- Notices to Mariners (UKHO)
- Notices to Mariners & Annual Summary (UKHO)
- Admiralty Tide Tables
- Admiralty List of Lights and Fog Signals
- Admiralty List of Radio Signals
- Sailing Directions (UKHO)
- Nautical Almanac
- Navigational Tables
- Tidal Stream Atlases
- Operating and Maintenance Instructions for Navigational Aids carried by the vessel
- Ocean Passages for the World
- Chart catalogue
- Chart Symbols NP Chart 5011
- Routeing charts
- Ocean Current charts and current atlases
- Ice Charts
- Distance Tables
- Guide to Port Entry
- Weekly Notice to Mariners
- Annual Summary of Notices to Mariners
- Navigation warnings (T & P Notices)
- IMO Ship’s Routeing
- Sight Reduction Tables
- Norie’s Tables
- Collision Regulations