Here in BC we are blessed with plenty of sheltered anchorages, and a good number of them are marine parks and as such are very popular destinations that fill up quickly. Few of these bays are truly shallow, making free swinging with adequate scope difficult if not impossible ( 7:1 'textbook' scope can rarely be practiced here)
As a result the only way to accomodate the large number of boats is for the majority to stern tie ashore, essentially eliminating swinging and opening up a lot more space in any given bay. In the Gulf Islands as result of glaciation many of the bays are long and skinny adding to the difficulty of using adequate scope to swing free.
Here are a few things we try to pay attention to when we anchor in this fashion:
In the diagram above, I've deliberately shown a couple of things that are not going to work.
It's crucial, of course, to factor in the expected tide changes for the duration of your intended stay. Grounding is a lousy way to wake up in the early hours.
In the picture, the clearance under the boat's sounder is probably enough to appear that you'd "stay afloat" at the indicated low tide, but as you can see the rudder will in fact be on the sloping bottom long before that. Knowing your bay and how steep the drop off is is helpful. The newer flashlight-sized battery powered depth finders are really nice to have to check the depth under the rudder when you're done setting up. Failing that a lead line (or a wrench on a string) can get the job done too.
Also, as the tide drops you need to be aware that your boat will slide aft both due to the increased effective scope on your rode, and the radius of the line ashore that will pull the boat closer. Remember in BC tidal changes of up to 15 feet are monthly occurences, with 8 - 10 feet normal daily.
More scope, and long lines ashore minimize this particular tendency to shift position but they also allow more lateral movement as the tide drops and/or a cross breeze develops, risking drifting into a nearby neighbour. In small coves in may be necessary to set two lines ashore to 'triangulate' and lock in your position relative to other boats (or rocks/shoals)
The orange arrow shows that the stern line is riding on the shore. If this is rocky, chafe can be a problem and it's a good idea to scrounge a driftwood log (or perhaps a spare fender) to lay under the line to avoid that
Shore tie lines should be brightly coloured, floating line. We carry 350 or so feet, many carry up to 600. These lengths allow the line to be led around the tie off point and back to the boat to allow retrieval without having to go ashore. However, retrieval can tend to 'saw' through the bark layer of a tree as the line is dragged around, so if you're going to use a tree, tie a sacrificial loop around the trunk and run your shore line through that. We generally leave the loop in the tree afterwards for the next guy. Try to avoid tying to the fragile Arbutus (Madrona in the US) trees. It's also a good idea to attach a fender to the line midway to shore to enhance visiblity for those dinghying around behind boats.
Most marine parks here have installed rings into the rock around the bay, usually flagged with surveyor's tape or a paint splash so they can be seen from the boat. These should be your first choice. In some areas where the banks/cliffs are tall there are chains and hoops hung from these rings for easier access from the water.
If you intend to stern tie, you should do some pre-anchoring preparations. Have your stern line flaked out so it will deploy cleanly. Many use reels nowadays, or stuff bags which can help avoid tangles, but we find reels very slow for retrieval. Have a tender or kayak ready to go ashore to run the line in minimal time... sometimes you're under the gun if the boat won't stay still while you go. Depending on the boat and the conditions, when pulling gently against your rode in reverse the prop walk may help hold you in place (or not....)
As with anchoring in general, work out some hand signals so that the rest of the bay doesn't hear you yelling at each other.. if the boat is happy to sit there, shutting the engine off helps communication too.
This technique will also make it possible to enjoy some real neat one-boat nooks and crannies once you're onto ways to "immobilize" the boat while in the hook.
Here the anchor's in about 80 feet of water, (no windlass between us
) and we're tucked into a tiny nook for overnight protection.
Now.. there is a major precaution here.. if your anchor drags, the first place you're going is to the beach (since you're literally tied to it!). Its crucial that you set your anchor well and avoid heavy cross winds and cross currents which can put inordinate loads on your anchor and rode. We were once in that situation, the water seemed to be literally boiling out from under the keel, current dead across the beam - and the anchor let go. We immediately starting arcing towards shore. Luckily we were aboard, and we cast off the stern line, the boat swung round and the anchor reset. We were lucky too that there were no other boats down-current... and we nearly got caught for not paying attention and thinking things through.
In the right time and place, though, and here in our summer season it's the only way to accomodate the numbers of boats in popular spots.