Anchoring With Care

Anchoring is an essential part of boating, whether you are stopping for lunch or sheltering from stormy conditions. Some seabed habitats, particularly seagrass, known as the rainforests of the marine world, may be sensitive to anchoring activities.

There are many simple things you can do when anchoring to both prevent damage to your boat and reduce your impact on the environment too.

Why key habitats and species need our protection:

Sediment seabeds

Intertidal and subtidal sandbanks and mudflats of European importance are habitats to a number of protected species such as seahorses, stalked jellyfish and rare seaweeds.

Seagrass and maerl are key habitats of the seabed, most at risk from damage and many sites in the UK are currently classed in unfavourable condition.

Seagrass (Zostera species)

• One of the most rapidly declining habitats on earth
• Scarce in UK seas
• Provide important nursery grounds for fish
• Healthy seagrass beds store significant amounts of carbon from the atmosphere, helping mitigate climate change impacts.
• Seagrass helps anchor and stabilise sediment reducing coastal erosion.

Maerl beds (Phymatolithon calcareum)

• Slow growing (<1mm/yr.) and are very fragile.
• Have a very limited distribution in England.
• Creates a very diverse habitat and supports an abundance of species.

The Green Blue has developed good practice guidance for anchoring in areas where there are protected habitats to help boaters preserve the marine environment they love.

Make sure that anchoring causes as little damage as possible to the seabed by following four simple steps:

1. Choose an anchorage away from the most sensitive areas wherever possible (e.g. away from seagrass, reefs, shellfish beds, etc.).
2. Deploy your anchor correctly to avoid drag:
   • Use the appropriate length of chain and warp to help reduce scouring of the seabed;
   • If your anchor is dragging, raise it and re-anchor; and
   • If it continues to drag, choose a different anchorage.
3. Even if you think the anchor is holding well, check it periodically to make sure it is not dragging.
4. Raise your anchor correctly when leaving:
   • Check to see how the boat is lying;
   • If the boat is pulling back away from the anchor, you may need to slowly motor towards the anchor as the crew pulls in the slack and raises the anchor;
   • Good crew communication is essential to avoid overrunning and fouling the prop; and
   • Bring the anchor and line on-board, and stow it away ready for immediate redeployment.

What else can you do to help?

It is also important to plan your approach with care to avoid damaging your boat, your pride and the seabed!

1. Know your depth and draft – smaller craft can reach shallower areas.
2. Check the tides – if in doubt slow down and use extra caution when boating on a low tide.
3. If you run into a seagrass flat, you will leave a sediment trail behind your boat, making the water murky and probably cutting seagrass fronds or roots. Stop immediately and lift your engine. Paddle away until clear. Never use your engine to force your way through, it will damage the seagrass and your engine!
4. If you run aground on seagrass, wait for the tide to lift you off again. Excessive use of the throttle in an effort to shift the boat will cause significant damage to the seagrass.

Why not look at our related guidance, including Boating Around Wildlife, Invasive Species prevention, Antifouling and Oil & Fuel to help keep our waters healthy and protect our wildlife and habitats.