Minimum Weight Anchor for H18?

I'm looking into getting a compact Grapnel anchor for my 18 and I'm wondering if anybody has a recommendation for the minimum weight it should be. I'd only be mooring it in sheltered water to use the boat as a swim platform, but 3.5 pounds seems like it's more designed for a kayak. Is 9 lbs enough? Or is it overkill? Any recommendations would be much appreciated.


Here's a link to the anchor I'm looking at:

https://www.amazon.com/Extreme-Max-3006 ... ods&sr=1-7

There are Grapnel Anchor sizing charts on the Internet as follows:

5-18 ft - 9 lbs
14-22 ft - 13 lbs
18-24 ft - 18 lbs

Of course, these are generic guidelines that don’t take into account specific boat type, weight, area, windage. So 9 lbs should be fine for “light duty” use on an H18. I wouldn’t go lower. But do use 10-15’ of chain and enough rode for at least a 4:1 scope.

Peter

The weight of the anchor may not be that important. I use an aluminium anchor (for my Hobie 21) that is very light but it requires a weighted rope and preferably a chain at the end too. Really any anchor needs a chain because it acts as a dampener for the waves. I would say that the weight at the end of the rope is more important than the weight of the anchor.

But in your specific use case anything will do.

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Hobie Cat 21SE #376

Anchor weight is important because the length of the flukes and the open width of a grapnel anchor (distance between fluke tips) increases with the weight. A 3 1/2 lb grapnel is not really suitable for anything much larger than a kayak or canoe as it cannot penetrate very deep into loose bottom material.

Peter

Depends on the type of bottom. If it's a sandy bottom, a grapnel anchor isn't going to work no matter what, you need a danforth (sand) anchor. If it's a rocky bottom, a small grapnel anchor would work just fine. The style anchor and type of bottom is much more important than the weight of it. The comments about length & weight of chain & line are spot on, especially if your anchor doesn't "grab" the bottom (like a hall or mushroom anchor), but an anchor plus chain plus a few dozen feet of line is a lot of weight to carry on a catamaran! You should anywhere from 4 to 7 times the water depth in line... so 5' of water requires 20'-35' of anchor line.

The best anchor stowage arrangement I've seen was on an 18 with wings. They tied a danforth anchor on the underside of one of the wings, with a short length of chain and a few loops of rope. Personally, I have a small grapnel anchor and 50' of line that I throw in the hull when I think I might want to have it aboard, but fully knowing that in most cases it's useless to me, unless I find a few rocks to pile on it/behind it... or if I get in a really bad spot near a rocky shore. It's probably 3.5 lbs, definitely not enough for anything but a very rocky bottom.

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Mike

'79 H18 standard 'Rocketman II' sail #14921 RIP
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