Anchoring in Currents/Wakes/Wind. Ideas??

[ssullivan]

In an anchorage I have moved to recently, I am presented with a challenge:

The anchorage has a current that sets (and drifts) East and West.

Not far from this anchorage is the main channel for the entire region, full of lobster and fishing boats on weekdays and absolutely choked with recreational vessels all weekend. This main channel also runs East/West.

The open ocean (Atlantic) is in a SW direction from the anchorage.

So... what is happening is that my boat is facing East or West (due to current, which is a few knots). This means I'm broadside to ocean swells entering from the SW and also (more annoyingly) to the incredible number of wakes from the main channel.


I was thinking about setting an stern anchor to keep myself oriented in a South-South West type direction, but I have a question:

Is it wise/safe to set a stern anchor in such a current?

If you picture a boat sitting *across* a current with an anchor out in either direction, straddling the direction of the current, my mind's eye finds that there would be more force on the anchors than if you simply had one anchor out - and that one anchor was simply holding the boat into the current.

Is that little assumption correct?

I envision it like when your boat is standing off a dock due to wind. Sometimes, you have to push the dockline *down* or *up* to gain the mechanical advantage to pull it closer to the dock. The current in this case would be given the same "mechanical advantage" in this case, wouldn't it?

What other ways are there to deal with such a situation, anchoring in a current of a few knots?

PS: I don't even know if the stern anchor will work because I have 10ft tides here and there is a heck of a lot of slack in the anchor line at low tide when the scope goes out to nearly 20:1.

Any input or advice?

[sestina]

What you need is an "anchor spring". This explanation will as seem as clear as mud!

Tie a line with rolling hitch on to your anchor chain. Veer off a boat length or so of rode. Pull in on your anchor spring making it off towards whichever quarter is appropriate.

Voila! Your boat is now held on a bridle, side on to the current, but with her head to the swell/wake.

[GordMay]

See also:

http://www.cruisersforum.com/forums/...lines-653.html

And:

http://www.cruisersforum.com/forums/...fort-7087.html

[cooper]

Pardon the pun, but I get your drift. If I understand what your saying...If you make sure that your bower is well and truly set, and that you set up a light stern, if pressure came to bare and the stern broke out would it matter ? Do you have enough room to swing? If I am right in what you are thinking, I would say yes...broad side on will increase the load strung between two anchors. If you have room and can swing.....Set yourself up...how you would like .....layout (flake) a reasonable amount of line on your aft deck ( even in a shopping bag works!) and attach it with a piece of something...(a couple of roves of knitting wool is strong).....What happens ....you get a little peace but if it gets up... the loose rode breaks. the boat swings... and then you extract your stern anchor and re think. I only say all of this because you are in a "crowded anchorage. " If you where in something more isolated then I would advocate a more robust solution. ....does that make sense ???

[ssullivan]

You answered this question a long time ago, Gord. Nice article, BTW. Good description.

So, given that the current reverses 4x a day, and the boat will swing each of those times, plus any time the wind changes, is this something that people at anchor long-term usually do? I could see it becoming something of a part-time job keeping the boat into the swells/wakes.

[ssullivan]

Originally Posted by cooper

Pardon the pun, but I get your drift. If I understand what your saying...If you make sure that your bower is well and truly set, and that you set up a light stern, if pressure came to bare and the stern broke out would it matter ? Do you have enough room to swing? If I am right in what you are thinking, I would say yes...broad side on will increase the load strung between two anchors. If you have room and can swing.....Set yourself up...how you would like .....layout (flake) a reasonable amount of line on your aft deck ( even in a shopping bag works!) and attach it with a piece of something...(a couple of roves of knitting wool is strong).....What happens ....you get a little peace but if it gets up... the loose rode breaks. the boat swings... and then you extract your stern anchor and re think. I only say all of this because you are in a "crowded anchorage. " If you where in something more isolated then I would advocate a more robust solution. ....does that make sense ???

Thank you, Cooper. I am not in a crowded anchorage anymore. I have been on the move. There are only a couple of boats here in this new spot.

What you describe is also a good idea... having a "weak link" to allow a stern anchor to come loose if it gets too much strain. Yes, my idea is to definitely use the primary anchor as the main holding point, but to have some technique to point the bow (or stern) into the wakes/waves to make for a more stable platform to live/work from.

Only trouble is those 10ft tides. If I set the stern anchor for a nice fit at high tide, I'll have a lot of slop in the line at low tide, and will probably not be facing in the desired direction.

(I think...)

[imagine2frolic]

Set it up on both sides, and let the one not need become relaxed.

[cooper]

Ok ... so ..you cant have it tight at low....for obvious reasons if it is a good tide and you want to have dinner and go to bed. BUT you don't want it sloppy at low because it makes it uncomfortable....I am not sure but I think the answer may be where yo put your stern anchor. Rather than putting it directly abaft..can you put it say 45 deg or even more to the bow. It should still hold you in the line that you want....but as the water level rises the "acute" angle will still hold the same. Again as long as you have the room , once the tide changes you will do a big swing..... and start again....

just a thought..

[Lodesman]

Originally Posted by ssullivan

You answered this question a long time ago, Gord. Nice article, BTW. Good description.

So, given that the current reverses 4x a day, and the boat will swing each of those times, plus any time the wind changes, is this something that people at anchor long-term usually do? I could see it becoming something of a part-time job keeping the boat into the swells/wakes.

Sean,

If you want to keep your bow into the swell, then you should rig 2 sprung rodes a la Gord's suggestion - spring your bower off the stbd bow to the west, and spring your stern anchor off the port quarter to the east. The tide shouldn't matter as you will only be riding to one at any given time, depending on the current.

Kevin

[ssullivan]

Update:

I tried Gord's method and it's been working fairly well. The only reason I didn't go for the stern anchor was that I might have had to buy some rode and rig up some extra stuff.

I was able to do Gord's technique without leaving the boat at all.

Benefits:

*Holds me oriented correctly the entire time the tide ebbs or flows, since it's not so windy here.
*Easily done with stuff I already had on board
*Used the rolling hitch... worked well
*Tied off to one of the 6 various cleats I have around my deck (it's a square deck - catamaran)

Drawbacks:

*Got hung up on the skeg and rudder
*Then got stuck on the saildrive (when current reversed)
*Anchor rode and extra spring line tend to go under the hull and gnaw away at bottom paint

But.... it's working well and I'm going to stick with it.


Thanks, Gord!