Marine Environment

MARPOL is the international framework for preventing pollution from ships. Its annexes address oil, sewage, garbage and harmful anti-fouling systems, and relevant requirements are implemented in UK law. MCA guidance says pollution-prevention legislation generally applies to pleasure vessels, while particular equipment, certification and discharge provisions can depend on the vessel's tonnage, voyage and certified carrying capacity.

A Coastal Skipper should turn that framework into a simple passage routine. Identify what can escape from the yacht, prevent it entering the bilge or sea, retain it securely where practicable, and know which shore facility will accept it. Add environmental checks to the same plan that covers weather, tides, pilotage and contingencies.

National guidance is not a standing permission for every harbour, inland waterway, protected site or foreign coast. Check current notices, harbour directions, local signs, charts and destination guidance. Brief the crew before the first consequential action, including refuelling, using the heads, handling rubbish, approaching wildlife, anchoring or starting maintenance.

MCA guidance says oil should be retained aboard for disposal to shore reception facilities. A pleasure vessel below 400GT is not required to install approved oily-water separating equipment, so the practical small-yacht default is not to pump oily bilge water overboard. Find and stop the leak, recover free oil with suitable absorbent material or equipment, and follow the marina or waste facility's disposal route.

Prevention includes a clean bilge that makes new contamination visible, an inspected drip tray beneath the engine, sound hoses and joints, an accessible spill kit and a crew member who knows how to stop the transfer. Before refuelling, confirm the correct filler and expected quantity, control ignition sources, keep vulnerable openings protected and attend the nozzle. Slow the delivery before the expected full level; fuel appearing at a vent is evidence of overfill, not a normal stopping method.

If fuel escapes, stop the transfer and close the source if that can be done safely. Raise the alarm, protect drains and water, use the facility's absorbent pads or booms, and contact the fuel berth or harbour authority as required. Detergent, hosing, propeller wash or dilution spreads or hides the pollutant instead of recovering it.

MCA MGN 599 Amendment 1 says the UK sewage provisions it describes apply to ships on international voyages over 400GT, or smaller ships certified to carry more than 15 people. It also says those regulations make no specific sewage provision for vessels below both thresholds. That distinction matters: the large-ship MARPOL equipment and discharge regime must not be presented as though every cruising yacht has the same legal configuration.

The same guidance gives a clear best-practice baseline for smaller pleasure vessels. Return waste to shore where possible; use a holding tank if fitted and empty it at a pump-out station. If shore disposal is impractical, its UK advice is to empty a holding tank only more than 3 nautical miles offshore in open sea where dispersion is effective. A yacht without a holding tank should avoid toilet use in poorly flushed estuaries, inland waterways, inlets and crowded anchorages by using shore facilities wherever possible.

The offshore advice is not a worldwide permission. Harbours, inland waterways, protected waters and other countries can prohibit or more tightly control discharge. Trace the system before departure, label valve positions, confirm capacity and pump-out availability, and make sure a crew member cannot accidentally select an overboard route in restricted water.

The IMO's simplified Annex V overview says garbage discharge is prohibited unless the annex expressly permits it. Plastics, synthetic rope, fishing gear, cooking oil, paper, rags, glass, metal, bottles and similar refuse are prohibited outside and within special areas. When garbage is mixed with another harmful material, the more stringent requirement applies.

Outside special areas and Arctic waters, comminuted or ground food waste that passes through a screen no larger than 25 millimetres may be discharged only when the vessel is en route, as far as practicable from land and more than 3 nautical miles from nearest land. Food waste that is not ground needs more than 12 nautical miles. Within special areas and Arctic waters, qualifying ground food waste needs more than 12 nautical miles and the unground-food exception is not available. Additional local requirements can still apply.

A cruising yacht rarely gains enough value from those exceptions to justify classifying waste, checking area status, confirming processing and measuring distance at the moment of disposal. Secure all rubbish aboard, prevent loose items escaping when the yacht heels or a hatch opens, and use a suitable shore reception facility. Vessels over 12 metres length overall also need the applicable garbage placard described in MCA guidance.

The current Marine and Coastal Wildlife Code applies to England. It advises motorised craft to stay at least 100 metres from marine wildlife, remain below 6 knots at no-wake speed, move farther away when disturbance is seen and keep clear when more than two craft are already nearby. Scotland, Wales and Northern Ireland publish their own guidance, and a local authority or protected site can add a different or stricter measure.

If dolphins, whales or porpoises choose to approach, maintain a steady speed and direction and let them end the encounter. Do not chase, crowd, encircle, feed or intercept wildlife for a better view. Head-on or close astern approaches reduce the animal's room to choose. Sudden course or speed changes can also increase collision or propeller risk.

An MCZ or SAC identifies protected features and a management framework; it does not itself tell the skipper that every activity is banned or allowed. MMO byelaws can control anchoring, vessel speed, entry, seabed disturbance, particular activities, zones or seasons at named sites. Check the current measure, chart, local notice and signs for the actual place.

MMO guidance explains that anchors and chain can uproot, expose, scar and fragment seagrass. It advises checking mapped sensitive habitat, using advanced mooring systems where provided and respecting voluntary no-anchor zones. The same reasoning applies to other protected seabed features identified by the site's current management information.

A charted seabed abbreviation, depth contour or apparently bare patch is only part of the decision. The skipper must also check current habitat information, local restrictions or requests, available swinging room, expected weather and tide, the yacht's anchoring system, the quality of holding and the escape plan. A visitor mooring is useful only when it is authorised, suitable for the yacht and conditions, and inspected or used within the operator's stated limits.

Lower the anchor under control at the chosen clear position, lay the cable without dragging it across habitat, verify holding using the vessel's normal checks and monitor the result. When leaving, recover vertically as conditions allow rather than motoring the chain across the seabed. Do not use propeller or water-jet wash as a way to clean gear over sensitive habitat.

Current UK anti-fouling controls are broader than the old shorthand that only TBT is banned. MCA MGN 398 Amendment 1 records that ships must not apply or reapply organotin compounds acting as biocides, and must not apply or reapply anti-fouling systems containing cybutryne. Existing coatings and survey or declaration duties have further vessel-specific provisions, so use a compliant system and obtain competent advice when a coating history is uncertain.

The RYA's practical sequence is Protect, Collect, Dispose. Protect the ground, water, drains, neighbouring boats and people before work begins. Collect wet scrapings, sanding dust, flakes, wash water and contaminated consumables at source. Dispose through the boatyard or local waste route specified for the material rather than leaving rain or wind to move it.

Follow the product's preparation, personal-protection, application and disposal instructions and the yard's rules. Dry sanding, pressure washing, solvents and cleaning products can each create a different exposure or waste stream. 'Biodegradable' or 'eco' marketing does not prove that a product may be released directly into the water; minimise use and keep residues out of the marine environment.

A longer passage increases the chance that one weak routine becomes consequential. Fuel transfer may happen at an unfamiliar berth, the holding tank can approach capacity, waste must stay secure through rough weather, the preferred anchorage can be unavailable and a wildlife encounter can occur while the watch is already busy. Responsible seamanship assigns controls and alternatives before those pressures combine.

Build decision triggers into the passage plan. A new bilge sheen stops automatic pumping and starts leak identification. Holding-tank capacity below the planned reserve triggers a shore-facility or itinerary change. A full visitor mooring field triggers the habitat-safe alternative, not an improvised drop into a mapped bed. Wildlife disturbance, a new byelaw or local sign, and a fuel spill each trigger an immediate, named response.

Record the source and time of important local information in the same practical way that navigational notices are recorded. The purpose is not bureaucracy; it lets the next watch understand which rule, facility status or site measure shaped the plan and when it needs checking again. If an incident occurs, protect life first, stop further pollution where safe, use the local reporting procedure and preserve an honest record.