Advanced Mooring Systems (AMS) are a practical, innovative way that we are reducing seabed damage that can occur from the anchoring and mooring of recreational boats.

We have been installing and trialling AMS within the five Special Areas of Conservation that ReMEDIES is focusing on.

We use the term Advanced Mooring System to convey that they are not just better for the environment but can also be better for boaters and owners. Manufacturers of AMS with elastic risers report reduced loads on boat connections in harsh weather, reduced motion during normal conditions, less maintenance and greater longevity than traditional chain moorings, which typically need replacing every few years.

Three images of a boat tethered to different styles of mooring. The first is a traditional swing mooring, the second an AMS with elastic rode, the third is an AMS made with a chain with four floats attached, holding it above the seabed.

Figure A

Traditional swing moorings are most commonly used in UK waters, consisting of an anchor, chain (rode) and float. But they can result in abrasion to seagrass beds. As the tide rises and falls, differing amounts of chain will lie across the seabed, and will be pulled around in a circle as the tide and wind direction changes. Abrasion from the chain can remove leaves and shoots, as well as the rhizome system.

Figures B and C

AMS are specially designed to reduce the interaction between the mooring and sensitive seabed habitats, including seagrass and maerl beds. These moorings are better for the environment and for boats.

How are AMS installed?

Some AMS, like the Stirling system (see photo below) use traditional materials. This can allow the materials from existing moorings to be reused.

Other AMS are purpose-built using new technologies, such as the Seaflex mooring (see below), which uses elastic rodes.

The ReMEDIES project is trialling a variety of designs, including Stirling, Seaflex and Hazlett. These systems can be attached to helical screws or existing concrete blocks, where removal may be more damaging than allowing them to remain.

Helical screws are driven up to 4 metres into the seabed, and must be installed by skilled divers when used subtidally. They can also be used for intertidal moorings.

This video shows the installation of a subtidal helical screw.

Stirling mooring, Cawsands
Stirling mooring, Cawsands
Seaflex mooring, Cawsands.
Seaflex mooring, Cawsands.

What have we installed so far?

The ReMEDIES project has built on the success of previous trials of Advanced Mooring Systems by the Ocean Conservation Trust and Marine Conservation Society.

Plymouth Sound and Estuaries Special Area of Conservation (SAC)

We identified opportunities and willing volunteers for AMS trials in Cawsands Bay. Ten Stirling AMS and three Seaflex AMS were installed in 2021 and 2022.

These are all private moorings and replaced existing traditional block and chain moorings. We will be gathering feedback from mooring users on the effectiveness of these systems and monitoring the impact on the seagrass beds.

During Summer 2021, advanced mooring system designs were also installed as swimming zone markers in Cawsands and the Voluntary No Anchor Zone (VNAZ) at Jennycliff to further demonstrate the use of these systems on sensitive habitats such as seagrass beds.

Fal and Helford SAC

Two AMS-style markers have been installed in Helford, alongside three existing markers, to clearly mark out the extent of the VNAZ there.

Solent Maritime SAC

Four AMS were installed in Yarmouth Harbour in 2020 and 2021. After monitoring their performance, the harbour are keen to install more AMS and are also interested in trialling their own design.

Two new AMS were installed at Cowes Harbour in December 2022.

A Voluntary No Anchor Zone has been installed in Osborne Bay in March 2024. 8 marker buoys signify the area of seagrass in the Bay, shown on the map below.

More information on current installations and projects involving advanced mooring systems in the UK and worldwide can be found here:

 

AMS UK knowledge summary note May 2024

 

Cawsand Bay
Cawsand Bay
Jennycliff Bay VNAZ
Jennycliff Bay VNAZ
Solent Maritime SAC
Solent Maritime SAC
Fal and Helford SAC
Fal and Helford SAC
Osborne Bay VNAZ
Osborne Bay VNAZ

AMS around the world

NE_AMS infographic final

Global AMS Report

In 2023, we commissioned a report detailing the various types of AMS manutactured worldwide and compiled a global database of boat mooring AMS installations.

The review identified 19 different AMS technologies currently available on the market.

A number of case studies also had evidence on the performance and success of the installations, though many did not have this kind of data available.

To read the full report, please download it below:

AMS Worldwide Review, March 2023

Get the practical guide

You can find this AMS information and other practical advice in our publication ‘The Green Guide to Anchoring and Moorings’, created with The Green Blue – the joint environmental awareness programme of our partner the RYA and British Marine.

Check our FAQs page for more information about AMS.