Anchoring as alternative to mooring

[Sire]

... in a very sheltered bay on a lake?

I've been thinking about where to keep my boat this coming season, and one possibility might be the place where my SWMBO's family have a small cottage by lake Saimaa.

I was wondering about using a heavy anchor as a semi-permanent (ie all summer) mooring? The location in question is extremely well sheltered, only open from one direction in fact, so the boat could be anchored and kept aligned with the prevailing wind by a stern line to the shore.

The boat is a 17' trailer sailer, and as Bruce style anchors are what is available easily and inexpensively here, I was thinking maybe something around 7 - 10 kilos? The water is only around 1.5 - 2m deep so I can easily check visually that it has dug in well to the sandy mud bottom.

My work takes me away for periods of up to 2 weeks, and the cottage is in use primarily at the weekends, so it would be potentially unattended for a week or so at a time.

I've made a quick sketch on the back of a grubby envelope - the structure on the right is a swimming jetty.

Anybody have any thoughts? Thanks!

 

[BobnLesley]

Should work fine; though if Bruce anchors are inexpensive and easily available to you, I would either use a good big one - in your case perhaps 15-20kg - or alternatively, two 7 - 10kg ones set perhaps 30 degrees either side of the prevailing wind, coming to a single riser; we've seen many 'moorings' that are done with two or even three anchors, as opposed to sinking a big lump of concrete/old engine block on the bottom.

 

[blackbeard]

If the anchor goes to the bows but the shore line goes to the stern, there's a risk of the boat being held at an angle to the wind; if there's not much ballast, or it's internal ballast, which might be the case for a small trailer sailer, it might be blown over and fill. Though in the location you show, this might not be likely since it's sheltered.

I'm told that larger Bruce anchors will hold much better than smaller ones, since they will dig in better.

Be wary of Bruce copies. Small but vital changes in geometry can reduce holding power. Might depend somewhat n the nature of the bottom (rock ?mud?). Also cheap copies have been known to break.

Plan B, for a small trailer sailer, would be to haul it ashore when not being used.

 

[onesea]

Keep an eye on ebay or any other local places to buy boats for an oversize boat anchor or two 20kg plus chain. I would not worry about bruce only, Danforth are good in sand lay in opposing directions get it right and you can leave it there for next year or retrive and lay again the next year. If they are heavy enough CQR (as long as dug in) or many others will do...

 

[ghostlymoron]

I certainly wouldn't rig a fore and aft mooring. Swinging is much kinder on the boat and puts less pull on the anchors. As suggested earlier, why not lay 2 big anchors, central swivel and riser terminating in a mooring buoy the you can use it every year.

 

[vyv_cox]

My mooring on the Menai Strait, just about as exposed as is likely for a mooring, suffering strong tides and strong winds on occasions, used two fisherman type anchors on ground chain. They were both very heavy, as was the ground chain, but perfectly acceptable.

 

[Kelpie]

Is there an equivalent of the Crown Estate in Finland? Just as a thought, I believe the legal difference between a mooring and anchoring is whether the gear can/is lifted and stowed aboard the boat. Probably doable with the type of gear needed for a 17ft trailer sailer.

 

[oldbilbo]

What you propose was once fairly commonplace, except that 2 semi-permanent anchors were used, and their chains laid out straight, aligned with the direction of the principal wind/tidestream. These were joined at the spot where the boat was to be secured, and a length of chain ( the 'riser' ) taken up on deck and secured to bitts or a samson post as normal. The riser was lowered to ensure the 'point of join' of the two chains was below the boat's keel/hull.

Of course, both chains could be brought up on deck over the bow, provided they were joined as above and the 'join-point' lowered below the keel.

This was a traditional mooring technique that the majority of working ships would use while awaiting their turn alongside a quay for loading/unloading, and you will find plenty of that knowledge, still, in the Aland Islands and nearby.

You could conceivably take your second ( long ) chain/line to the jetty, but I would still consider it essential - as mentioned above - to have both chains/lines come up over the bow and NOT have one led from the stern.

 

[srm]

I used to leave my boat unattended on her own anchors for a week or so at a time while cruising around Shetland in the 70's. The anchors were on the big side for the boat, (a habit I have been glad of on a few occasions since). At first I laid the two anchors and cables in opposite directions, but after a while found that lying to one chain was easier to recover. I then laid the two anchors in tandem towards the most exposed direction, and never had any problems. If intending to return to the same anchorage I lifted the first anchor when leaving and buoyed off the second.

 

[Twister_Ken]

I suspect any problems might be legal, rather than technical. Who owns the lake and lake bed, and do they take income from moorings on the lake. If so they might consider by 'permanently anchoring' you have, effectively, laid a mooring, and thus want to charge you or throw you off the lake.

 

[William_H]

As said a swinjg mooring or anchoring is far more gentle on the boat and hence on the mooring gear. If you use one anchor then if the wind chnages by 180 degrees or so then the anchor will be uprooted and reset and the boat will move by twice the rode length. That means for 3 metres of water something like a 25 metre diameter swing circle.
Far better as said is 2 anchors on each end of a chain with mooring taken from the middle. In effect if wind changes by 180 degrees it pulls on the other anchor and does not rset any anchors. The swijng area will be about 8metres diameter. Further if one anchor does get over powered by pull then it will drag until the other anchor lies parallel to it wso hopefully ou have twice the holding power.
It can be a bit of a trick to set the anchors. Diving down setting the last is best but you can just drop the anchors and have the joining chain slack with the centre mooring attachment near the surface, the join being made from a dinghy.(put some weight at the centre to hold it down a bit. For more security you add more anchors and chain at large angles to one another. Of course you leave the mooring with a buoy when you go sailing. good luck olewill

 

[Twister_Ken]

Of course you leave the mooring with a buoy when you go sailing. good luck olewill

In which case you've laid a mooring, not an anchor. Not sure if this is what the OP wants.

 

[Sire]

Thanks very much for all the replies.

The idea of tying the boat up like that comes out of the necessity of keeping it out of others' way. If I were to anchor further out, then I would likely be blocking the narrow channel that the owner of the property at the head of the bay dredged to make access for his rather larger boat. Also it might start to bother those who have cottages on the other side.

The location is really well sheltered - the area surrounding the bay is wooded and it slopes, and the chance of any significant wind from any direction other than indicated is extremely small. Further up towards the mouth of the bay, a cottage owner there has made own moorings of the traditional Scandinavian variety, that is to say a stern buoy and the bow tied to the shore. There isn't really enough room for me to do the same; anyway if I did the wind would be from the side, and that whole arrangement just seems to have way to much "comedy potential".

As it is, the system I propose still has potential for things going wrong - I certainly wouldn't get two chances to pick up my anchor buoy.

[Edited to add:]
Keeping it on the trailer isn't really a solution if I'm going to actually use the boat. Launching and recovery from the trailer I have has always been a challenge - the previous owner always had her craned in and out. The original sales brochure from the 70's shows her being towed behind a Datsun 100A, and launched singlehandedly and effortlessly by a waif-like lady - the reality is that launching a half tonne of boat down a steep slope is very different from slipping a Skipper 14 in...

 

[William_H]

[Edited to add:]
Keeping it on the trailer isn't really a solution if I'm going to actually use the boat. Launching and recovery from the trailer I have has always been a challenge - the previous owner always had her craned in and out. The original sales brochure from the 70's shows her being towed behind a Datsun 100A, and launched singlehandedly and effortlessly by a waif-like lady - the reality is that launching a half tonne of boat down a steep slope is very different from slipping a Skipper 14 in...[/QUOTE]

Yes convenience of launching and retrieval is really about the slip or ramp that you use. Concrete is best. If it is too steep then you have a job pulling the boat out with a small car if it is too shallow you have to push the trailer in too far to float the boat on. Practice and thought full use of aids will help in both getting the boat off and on the trailer and of rigging the boat. Don't give up too soon. I find it relatively easy with my 21fter but stilll prefer to keep it on a mooring. good lcuk olewill

 

[Sire]

The problem is really with the trailer, which wasn't designed for this boat. I have modified it so that the boat can be transported, but the boat is carried relatively high and therefore has to be reversed a long way into the water even on the steep slipway that I have been using. A heavy 4wd, at the very least, is essential. Sometimes a friend with a large tractor has been able to help, and that makes it a bit safer and easier. Recovering the boat onto the steeply sloping trailer is a problem too!