Thursday, March 11, 2010

LRA - Larry's Remote Anchoring technique...

Our dinghy weighs about 800 pounds. She's a rigid inflatable with a 40 HP engine. It's our family car when we're cruising and we put a lot of demands on her.

So I was telling Larry how much of a hassle it is when bringing the dogs to the beach. Beaching the boat ends up pushing the whole boat sideways on the beach with oncoming waves and can become very difficult to re-float it when it's time to leave. Instead, we keep going back every 5 minutes to push the boat back into the water.

Larry had a solution. He always does. And this one is a doozy.

"You don't know how to use the trip line on the anchor to remotely anchor the dinghy?" Larry asks. Well, no, I don't. I've never seen anyone ever do it. With that Larry gives me the specs for what I need and explains exactly how to do LRA - Larry's Remote Anchoring.

First, the equipment and deployment.

I use a grappling hook type of dinghy anchor. LRA is real anchoring so I created a special rode of 5 feet of chain with 8 feet of 3/8" line. I attached a clip to the end of it so it could be attached to the bow eye of the dinghy close to the water.

The critical piece of equipment is 100 feet of 1/4 inch nylon line on a spool. That gets attached to the trip line eye at the bottom of the anchor.

With that all ready, this video shows the equipment and deployment at Sombrero Key.  We land in about 2 feet of water and push the boat out to anchor in 4 feet of water. Turn your sound up - it's hard to hear - lots of dogs hanging around the "studio".

The magic is in putting all of the equipment on the bow which is easily popped into the water by a slight tug of the trip line. The trip line is the retrieval device and an emergency line in case the anchor fails. It isn't good enough to hold the dinghy in a gale, but for going to the beach, it's plenty good enough.

Retrieving the anchor is just as easy.

It's all pretty easy to do. I strongly suggest using chain on the anchor if you're going to use this technique. Total cost for this was about $25 plus the anchor which we already had.

Now Larry, how about a trick for rinsing and drying off wet dogs before they get back onto the boat?


«Côte de Nuits» said...

Very good idea, thank you to share it.

Have a good trip.

Unknown said...

How does it work with an on shore breeze?

MV Red Head said...

Yeah - it works in all weather conditions. I've done it now about a dozen times. Sometimes the dinghy swings away from the beach, sometimes towards it. The key is making sure it is anchored far enough out so it can swing in any direction. The trip line is there so you don't have to retrieve it in 5+ feet of water.

Unknown said...

If you carry a sand spike you don't even need to find a beach with a handy rock on it. :-)

Anonymous said...

Two things; I could see the anchor not setting and the dinghy disappearing, or an unsuspecting dinghy operator gettin the trip line wrapped in his prop as he motors between the anchored boat and shore.

Anonymous said...

the trip line should be lying flat on the bottom, so hopfully should not get foulled in a passing boaters props. I think it is a great idea, and yes, to for strong wind conditions.

MV Red Head said...

We spent most of our careers creating medical products and have 9 FDA approvals for things we've created. One of the things that taught me is that you have to protection against single points of failure - all of our FDA-approved products needed to meet that. It's a great model. Guarding against multiple points of failure happening at the same time is just impractical - you can always come up with a situation of "what if this happens AND that happens"...

LRA protects against many single points of failure. First, it's real anchoring - anchor, chain, and enough scope - something that's not typically done on a dinghy. Anchor dragging (a single point of failure) is guarded against by the trip line on shore. In normal situations, that trip line has no stress against it and lies completely flat on the bottom. The trip line is going to stop any dragging. If then another boat has to come and cut the line, that's 2 points of failure - both of which have to happen. I'm OK with accepting that risk which is part of any boat outing.

A single point of failure that isn't protected against is a breaking of the anchor rode. Perhaps someday we'll add features to our mobile phone software that could provide a remote anchor alarm!

Unknown said...

Of course there is another way to do it that has been around for years.

And that is where you have a long loop of line that you loop through the end of the anchor chain and set the anchor as a stern anchor. Then head into the beach trailing the looped line behind you like you would a normal stern anchor line. Unload the tender and then tie one loop of the line to the bow cleat. Then pull the tender out from the beach with the loose loop of the line. The shackle on the anchor chain acting as your pulley so to speak. Once you have the tender out about half the length of the line you tie the line to something on shore. When you want to retrieve the tender you just pull it back into the beach, load up and then go out and pick up your anchor.

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