Need advice for anchoring an inflatable in Monterey

[mrfixitchapman]

I have a Mantus anchor for my 30 foot sailboat. It happens to be a 30 pound galvanized. When I put the anchor on the bottom and back down the thing sets like the tailhook on a Navy jet during a carrier landing. They have a new dinghy anchor that is really light weight. I'll be buying one of these for my 3-meter Zodiac dinghy. If it doesn't work I'll send it back for a refund, but I suspect that it will do just fine.

Mantus Anchors | Mantus Dinghy Anchor



Oh, and you SHOULD use chain ,(at least one boat length), to keep the anchor set. For my 30 foot boat I use 40 feet of 5/16" chain attached to the anchor. The anchor rope rode attaches to the end of the chain.

DC

 

[Chuck Tribolet]

I have had 3 or 4 danforth style anchors, including a Fortress and if the bottom was anything but sand, they just did not hook. ...and who wants to dive a sandy bottom anyway?

There's often a sand bottom right next to the reef, and it's much friendlier to the reef to anchor in the sand. And it doesn't get stuck in sand.

And some of our sand bottoms (e.g., the mouth of Whaler's) is some of the most interesting diving we have.

Chuck

 

[oldschoolto]

Well there's your first problem, mushrooms are useless in anything but a calm lake and Danforths are useless pretty much everywhere. Take a walk along the pier and you'll see that most boats (and all the dive charter boats) in the marina have a Bruce style claw anchor. Buy at least twice as much anchor as the manufacturer recommends and run twice as much chain. An 11- 16lb claw with 20 feet of 3/16 chain is cheap insurance and you can set it with less scope.

I don't know Jon... I see more Danforth anchors than any other on boats... A Bigger anchor is not better ... The right size for the boat and the right amount of chain and size rope with a scope of at least 3 to 1 .... Drop anchor and set it with reverse .... The boats not going anywhere...

Jim...

 

[Jon Nellis]

I would believe that in Maine or any where else on the east coast or GOM where the most prevalent bottom type is sand and mud. In California it is rock at most of the good dive sites.

If I were anchoring a boat for a lunch break, then yeah, there are a lot of anchors that will work and having a lot of scope is not that annoying, but The OP is asking about an anchor for a dive boat.

When you need to drop the hook on a tiny dive site 200 feet deep on a slope with a breeze blowing you to deeper water, A light anchor with a lot of scope will not work. $20-$30 more for larger anchor and an extra 10lbs of weight in the boat isn't really noticeable, but having your boat blow off the hook when a weather front unexpectedly moves in while you are underwater, is extremely noticeable. I have seen the wind shift 180 degrees in the middle of a dive. A well set, minimum sized anchor on an up slope will pop and float off in that case. I personally know someone that had their anchor pop off in 250 feet of water on an unattended boat, halfway through the dive. Wisely, they ran a reel from the anchor and spent 30 minutes decoing in blue water as it drifted over the 3000ft deep Carmel trench.

Even if you only go out in good conditions, conditions can change really fast. If someone is leaving the boat unattended while diving, a heavier anchor and some extra chain are cheap insurance.

Cheers,
Jon

 

[oldschoolto]

OK Jon... I'll buy that... And all my boating and diving is all east coast..

Jim...

 

[ineedavacation]

Thanks to everyone for the anchoring advice. I ended up using a 12lb danforth style anchor in about 70 ft in the sand channel of whalers cove at Lobos.

Here's what I learned:

1. Dinghys aren't easy to back up to set the anchor...especially when you are in a narrow channel surrounded by kelp. When I dove down the anchor line I found the anchor lying in the sand not buried.

2. Tell you buddy to duck before yanking the starter cord in a small dinghy.

We tried to anchor in Bluefish, but it was so full of kelp, I couldn't find a good spot. I motored back over to granite wall and had a good dive. Viz was about 20ft.

 

[Peter_C]

1 Typically I find my anchor buried under my chain. i do not try to set the hook before descending, since if conditions are anything but benign we do not go diving. Once on the bottom I set the hook and straighten the chain out to the current direction of pull (Wind, tides, etc could change direction).

2 I almost fell overboard a few times yanking hard trying to start my 40hp. It wasn't long after I put an electric starter on it, and am thankful every time I hit the button.

Bluefish is often covered in kelp. I just drive right into it, and keep an eye on my tell tale. Some people won't drive their boats into the kelp at all. Since I sit at the back of the boat with a tiller drive I can see if anything gets caught or plugged up on the lower leg, and it is easy to shut the boat down and clear the lower leg. To each their own.

If you don't have GPS it is time to get something, so you can locate dive sites. A sonar unit is nice to have too, as sometimes you need to drop anchor on or around a pinnacle. Of course a full blown GPS/Sonar requires a battery, although you could make do with handhelds. You should have a DSC equipped VHF radio while out on your boat too. West Marine had one on sale as of a week ago. I carry a Nautilus Lifeline also.