By: Blonde Two

If you visit the British seaside, you are bound to notice a buoy (and possibly a boy) or two bobbing around in the water. These spheres of plastic are different colours and sizes, have different purposes and sometimes come unhitched from their moorings. Over the August Bank Holiday weekend Mr B2 and I swam out to a buoy, took some photos and swam back into shore again. I even touched it, something I don’t usually like doing as I have a tendency to imagine all kinds of weirdness dangling below the friendly brightness. Buoy visiting makes for an unusual kind of expedition but I think I might be hooked (hopefully not like a fish). I would recommend this only in water you know, in areas relatively close to shore, with company and an onshore spotter and well within your known swimming ability. In case you need help choosing your buoy, here are a few bits of information about the different types of buoys in UK waters.

Five knot buoys

Swimming inside areas marked by these yellow buoys should, in theory, be safer than swimming outside them as they show a speed restriction to which all watercraft should adhere. Most do and keep a careful eye out for swimmers but it pays to be aware that not all craft are careful or even aware of speed restrictions, that not all beaches have these areas and that speed buoys are often removed during the winter months.

Navigation buoys

These larger buoys are used to mark safe passage for boats and are definitely to be avoided when it comes to swimming. Next time you are near a harbour, take a look for one example. Green and red buoys often mark the deeper channel, with red to port (left) and green to starboard (right) as you head into harbour. Trinity House are the navigation buoy experts with over 450 of their own buoys and inspection responsibility for those installed by other authorities.

Fishing gear marker buoys

If you are swimming around small, coloured buoys, the chances are that you are above fishing gear. Those leaving fishing gear in the water have a responsibility to set it outside navigable channels and make sure that it is clearly marked, in order to avoid entanglement issues. The Maritime and Coastguard Agency have some helpful information about these buoys.

Marine code buoys

As more craft take to the water, some marine protection associations have found it necessary to place marine code buoys that carry messages asking people to stay away from or limit behaviours in certain areas. These might be to protect fauna, e.g. seal populations, or flora, e.g. delicate seagrass beds. Some of these are placed within swimming distance of beaches and can make for interesting reading and sometimes give you an idea of what you might be looking for below you.

Mooring buoys

These can be small or very large depending on the size of vessel and location of the buoy and are designed to hold a boat in position. Different harbour authorities have colour coding systems for mooring buoys.

Weather buoys

As well as providing important weather information for those working offshore, weather buoys make a big contribution to computer models that predict weather and climate change. The Met Office has 11 moored buoys, each of which is over six metres tall, and around 1, 250 drifting buoys. You are unlikely to swim past these but you might be able to help with climate change in other ways.


These are a slightly different type of buoy as they are usually stored onshore to be deployed in an emergency. If you are visiting a beach, river or lake, especially if you are a swimmer, it is a good idea to note the location of lifebuoys and keep an eye out for people who might be in trouble.

We haven’t covered all types of buoys here but hopefully, we have given you a bit of information about these bobbing mysteries and made them seem a bit more friendly. After all, what is a bit of seaweed encrusted rope between friends?