Marine Environment

As a skipper you have a legal and moral responsibility to protect the marine environment. The sea is not a dustbin — everything that goes overboard has consequences for marine life, water quality, and coastal communities.

The MARPOL Convention (International Convention for the Prevention of Pollution from Ships) sets global standards. As a recreational skipper, you must be aware of your obligations regarding oil, sewage, garbage, and harmful substances.

Even small quantities of oil or diesel can cause significant environmental damage. A single litre of oil can contaminate a million litres of water. Never pump oily bilge water overboard — use absorbent pads in the bilge and dispose of them ashore.

When refuelling, take care to avoid spills. Use an absorbent collar around the fuel filler. Do not overfill tanks. If a spill occurs, contain it immediately and report it to the harbour authority.

Discharge of untreated sewage is increasingly restricted. Many harbours and estuaries are 'no discharge' zones. Use holding tanks where fitted and pump out at designated facilities ashore.

If the vessel has a marine toilet (heads) that discharges directly, only use it well offshore and away from bathing waters, shellfish beds, and environmentally sensitive areas.

Under MARPOL Annex V, the discharge of ALL garbage into the sea is prohibited, with very limited exceptions. Plastics must NEVER be discharged at sea. Food waste may only be discharged more than 12 nautical miles offshore, and only if ground to pieces smaller than 25mm.

In practice, the simplest approach for recreational sailors is to bring all waste back to shore. Separate recyclables and dispose of everything properly at marina waste facilities.

Be aware of marine mammals (dolphins, seals, whales) and avoid disturbing them. Maintain a safe distance — at least 100m from whales and 50m from seals hauled out on rocks. If dolphins approach your boat, maintain a steady course and speed; do not chase them.

Seabird colonies are especially vulnerable during breeding season (typically April–August). Avoid anchoring close to nesting sites and keep noise to a minimum. Be aware of Marine Conservation Zones (MCZs) and Special Areas of Conservation (SACs).

Seagrass beds (Zostera) are critically important marine habitats that provide nursery grounds for fish and food for wildlife. Anchoring on seagrass can rip it out and cause damage that takes years to recover.

Where possible, use moorings rather than anchoring. If you must anchor, choose sandy or muddy bottoms and avoid areas marked as seagrass beds on charts. Weigh anchor carefully to minimise dragging across the seabed.

Anti-fouling paint prevents growth on hulls but many older formulations contain toxic substances (particularly tributyltin, TBT, which is now banned). Use only approved anti-fouling products and follow manufacturer guidelines.

When cleaning or maintaining your boat, prevent paint scrapings, solvents, and cleaning products from entering the water. Use designated boat maintenance areas with proper drainage and collection systems.

On longer coastal and offshore passages, environmental awareness becomes even more important. Your vessel is self-contained for extended periods and every decision — from where you anchor to how you manage waste — has a cumulative impact on the marine environment. Responsible seamanship means actively minimising your footprint throughout the voyage.

When anchoring, always check charts and local notices for sensitive habitats such as seagrass beds, maerl, and biogenic reefs. Voluntary Marine Conservation Areas (VMCAs) may not carry legal restrictions but indicate ecologically important sites where best practice is to use a mooring or anchor well clear. Avoid using the anchor wash over seagrass — the powerful jet of water scours the seabed and can destroy fragile root systems even if the anchor itself missed them.

Wildlife encounters at sea are a privilege. If you encounter whales, basking sharks, or other large marine animals, reduce speed, avoid sudden course changes, and never approach head-on. Switch off echo sounders and fish finders if safe to do so, as the acoustic pulses can cause distress. Reducing engine noise by slowing down also lessens underwater sound pollution, which interferes with cetacean communication and navigation.

The Green Blue initiative is a joint programme by British Marine and the RYA that promotes environmentally responsible boating. It provides practical guidance on anti-fouling, sewage, cleaning products, waste, and wildlife — all freely available at thegreenblue.org.uk. Following Green Blue recommendations is considered best practice for all UK recreational sailors.

Sewage discharge regulations require that no untreated sewage is discharged within 3 nautical miles of land in UK waters. Holding tanks should be used within this zone and pumped out at shore facilities. Beyond 3nm, discharge is tolerated only if the vessel does not have a holding tank, but best practice is always to use pump-out facilities. Cleaning products used aboard should be phosphate-free and biodegradable — conventional household detergents and bleach can be toxic to marine organisms even in small quantities.