Cottage Q&A
QUESTION
We installed a swim raft at our cottage last summer. To anchor it, we used five concrete blocks on long
ropes, set out at far angles. With a strong current and a flat, granite-bottomed lake, the raft ended up a
long way down the shore. My husband added five more blocks, bringing our total to 10, but it still moved. Do
we need to don scuba gear, rent a waterproof drill, and put a big hook into the lake bottom? That doesn't
seem friendly. Any suggestions?
ANSWER
You don't need the scuba gear, the drill, or the big bad hook. You do need some different anchor materials and a different method, advises Astorville, Ont.-based dockmeister Max Burns, author of The Dock Manual, published by Storey Books.
Instead of rope, use 3/8" steel chain. It won't deteriorate anytime soon, and it will add some useful weight.
Instead of concrete blocks, you need some seriously heavy anchors. They should add up to at least double the raft's weight. (Don't stint on these, because each submerged anchor loses about one-third of its weight in the water.) Here's Burns' simple suggestion for making your own: Lay some polyethylene sheeting down on a flat surface, get some used 14" tires, and fill them (the tire insides and the centres) with concrete. While it's still wet, insert steel hooks into the concrete for attaching the chains. Make a bend in the shaft of each hook before inserting it, so it can't pull straight out of the hole once the concrete dries.
The resulting anchors should weigh about 115 kg each. But - and here's the really neat part - because they are wheels, you can manhandle them with relative ease by tilting them up and rolling them to the water.
If you know your raft's approximate weight, you'll know how many of these monsters you have to make - probably not more than four, one for each corner. Cross-chain them, i.e., criss-cross each pair of chains so that each corner is linked to the anchor under the adjacent corner. The chains should run at about 45° angles under the raft. If your raft still has a case of wanderlust, you can always gang more anchors at each corner.
* Published in the April/May 2005 issue of Cottage Life
Related links:
- In the Cottage Life Forum - see how other cottagers anchor their own swim rafts, complete with photos
- Article about the swim raft that Wayne Lennox built, including info on regulations
- Cottage Q&A article about swim raft
regulations
