Just a few thoughts on checking or salvaging moorings and mooring buoys for yacht and other boat owners in the Perthshire area on Loch Tay or Loch Earn.
We have had a couple of requests from yacht owners to look at and or salvage their moorings and also free props that have been snagged in floating line. While this is something that we can do and many of us have experience of , it is definitely a job of work and not a recreational dive. If payment is taken then you are subject to HSE regulations. To date we have had requests to look at and salvage moorings on Loch Tay, Loch Earn, at Oban and Loch Creran. I thought I’d put a few words together for everyone’s benefit, so if you are asked to do this sort of work then you have a good idea of what you are getting into.
Often boat owners who have a snagged prop will ask local divers to have look and see if they can free it. You need to be aware that this can be an objectively quite a dangerous dive in very little water and you need to access the conditions. On a flat calm day with no swell it can be straight forward and a rewarding experience to assist someone but when the boat is moving even slightly you need to be very careful you do not get pinned , crushed or damaged by only slight movements of the boat. A good tip is do not cut the snagging rope unless you absolutely have to and if you do, then leave long ends to give you something to grip. Most folk are happy to do this sort of work as a favour or a cup of coffee.
Snagged, lost or sunken moorings or obstruction removal are totally different and should be treated as a job of work. Typically , as boats revolve around their (single) moorings and where a swivel is not used, the mooring chains wrap around the anchors which then drags the mooring buoy underwater as any slack in the system is removed. To untangle this you have to find the chains radiating out from the collecting shackle to the anchors and untwist them. This is not an easy job as there is limited purchase underwater. One way of doing this is to mark each chain and shackle with a lifting/buoy and gradually unravel it, but it does take time and you do exert a lot of energy. Typically it is not possible to undo and reassemble a mooring underwater without cutting chains. Visibility on this sort of dive in saltwater is much better that in fresh where sediment is easily and unavoidably stirred up, so be prepared for a low viz dive.
If the buoy has been lost then an underwater search is required to find the chain and anchors. Finding chains in silt or mud involves a finger tip search.
I would suggest that if anyone was approached to do this sort of thing then they should in the first instance chat to the DO as it can be a very interesting project but make it clear that it would be done on a best efforts, cost recovery basis with a club donation made if club equipment is used. The DO should inform you that you will not be insured under either BSAC or club policies to complete any chargeable piece of work and that if you proceed you need to make it clear that it is on a best efforts and non-insured, no-liability basis.
So the first thing you need to do is understand what the problem is and what is required. Initial questions that could be used to form an assessment would be:
What seems to be the problem, how was it caused and what would be an ideal outcome ?
Where is the mooring, how do we get there? How do we get access to it (do we need a key?). Are we allowed to dive or do we need special permission?
How deep is the mooring?
How exposed is this site to tides and weather? (Unlikely if it is an anchorage however divers have different requirements from boat owners, this is important because usually multiple dives are required, and you will need to warm up during surface intervals )
How is the mooring laid and is there any fouling and what is the substrate (Ie is it safe to dive) – draw a diagram
Can we launch a boat for surface cover and is there adequate safe space on the shore for cars and equipment.
Finally having made an initial assessment agree any costs up front.
Costs which would be typical of any recreational club dive might include:
Towing the boat to and from the site and car/diver transport
Petrol for the boat engine if used and club levy on the use of boat
Cost of compressed air
Having made your assessment you have to consider if it is appropriate to continue and you have a reasonable chance of success under the conditions. Talk about it with other club members and do your research. Plan what needs to be lifted and what tools will be needed and how these will be secured. Consider visiting the site before you actually do the work. Finally remember that safety is paramount and if you are not happy then either discuss with someone more experienced or leave it for another day.
One final comment, as recreational divers we should be sympathetic towards the environment in what we are asked to do. We should also consider our actions in relation to any protected or endangered species or however unlikely, archealogical sites.