How large a dinghy can I carry?

[Fishspearit]

Ok, I thought I'd throw this out to the community for opinions. I'm planning out davits and dinghy for future cruising. The boat is 39' (11.9 m)long, the beam is 13' 2"(4 m), and the beam at the stern on deck is 8-1/2' (2.6 m). The deck is 3-1/2' (1.1 m) off of the water, and the rail is 2' (.6 m) above the deck.

While I would love to have a hard dinghy, I've yet to find one that I think is light enough, small enough, and still able to plane. So I'm likely stuck with a RIB, and I'm thinking I can probably safely carry a 10' (3 m). But I've never owned a boat with davits, and I'm not sure how 9" of overhang on each side of the stern would behave.

I also have an issue with putting a dinghy on the foredeck, since I've got a stay up there that is in the way. I don't know what you call it, it's not a stay for a cutter sail, it hits the deck about 5 or 6 feet in front of the mast and goes half way up. But it makes the space between it and the windlass too small to lay a 10' Rib. So whatever I get will probably live on davits full time or have to lay across the aft cabin top. Not planning on circumnavigation, just coastal cruising with short hops into the blue like crossing to the Bahamas and between the islands.

So what do you think, can I carry a 12', or only an 8', or would 10' work?
Also, with the beam 8-1/2 feet at the stern, how far apart should I be putting the davits, 6 feet?

[MarkJ]

Originally Posted by Fishspearit

I've got a stay up there that is in the way. I don't know what you call it, it's not a stay for a cutter sail,

Its called a Baby Stay.

But for the dinghy question I have no advice. I love our roll up dinghy because we have a large lazarette to stuff it and don't mind it being small. However I can understand the convenience of a biggie with davits!

[Bradley]

a 12" dinghy??? That is liveaboard size. A 10' would be the max. The lighter the better. It seems the majority of cruisers have a 9" dinghy. I have the AB aluminum dinghy and am very happy with it. I had a Carib that was stolen. The 70 pound weight differential is noticeable.

[Vasco]

I have carried a dinghy on davits that was wider than my stern. Just have to really watch it when going alongside bulkheads or tall piles. I would go with a 10'06" RIB. Put the davits as far apart as possible. This site has good instructions re davits.
Ocean Marine Systems - Davits, Rails, Lifts, and Platforms.

[kai]

i was just wondering if any one has ever used a opti as a dinghy(7.7ft, 77lbs )? i was thinking this would apply more to the long time cruising could be fun and versitile. im not sure if oars could be installed on the dinghy but it could be sailed right up to the beach. i was just thinking.

[Pblais]

We have had davits on both the past two boats. When you have a boat on it you really can't tell until you get into close quarters like as Rick says pilings are just too magnetic it seems. Pinned against a bulkhead can be tricky getting off since the back end needs room to swing. You can get RIB's from 8 to 10 ft and that seems the most practical range with 9 being the most common for carring two ppeople and some luggage. At 12 feet you are carrying a lot of weight and not getting much back for youir efforts. The size of the engine grows and an engine hoist becomes manadatory instead of desirable. An engine hoist is desirable so you can get the engine off the mount and onto the dinghy and back again.

Being able to handle the dinghy when you are not actually using it is the key problem you have to deal with.

[svquest2]

12' would really be pushing it but On a 37 footer with an 11-6" beam I carry a Caribe which is 10'-3". It is a hard bottom inflatable with a center console and is quite heavy. I also store it with the motor attached but then again I have a pair of very skookum davits, with a 1500# electric winch on each. Originally they were a little too low so I remounted them on 8+" blocks to get the dinghy a little higher. I have gone from WA to Mexico and spent 6 years cruising the Sea of Cortez and never had a problem. Oops, not quite true. I once went south into a strong southerly and going over one large wave with the dinghy improperly secured (I was a little lazy and didn't expect the waves) the dinghy flipped completely upside down onto the top of the davits, then slopped aft and hung sidewise in both davits dropping some things that were in it and spilling almost all the gas that was in the fuel tank. The fuel cap wasn't on but I hadn't known it. It strained and cracked the fiberglass at the forward joint where the mounting blocks joined the deck but that was all. Lesson: make sure the dinghy is properly secured in the davits before going to sea.

[Benjamaphone]

Originally Posted by Fishspearit

how far apart should I be putting the davits, 6 feet?

The space between the davits is determined by a couple factors. First, where can they mount. It looks like you have a lot of free space all along your transom and so that doesn't really play out too much. The next biggest factor is where your pick up points are located on the dinghy. The pick up point on the stern of dinghy must be far enough forward so that the motor will clear the davits. The forward pick up point will then be mounted about an equal distance from the bow.

An 8' or 10' dinghy would be ideal and the highest engine should be 15-25 hp, which is enough to get a nice hard bottom up on plane.

Davits can either be rail mounted, deck mounted or transom mounted depending on what else you're looking for. There are also davits with a stainless steel tube construction and/or solid cast davits. S.S. davits have a lower safe working load but they can rotate and be more easily removed. Solid cast davits are more of a permanent fixture, though they can include a removable shoe that hastens removal, and can handle extra equipment such as solar panels.

Quality davit manufacturers produce davits that come in many shapes, sizes and perform several different functions. Choose a dinghy that you like and that is not over sized for your boat and there will be a set of davits designed for you.

[Fishspearit]

I thought I'd go ahead and update this old thread with my end result. I ended up going with a set of rail mounted davits, a Caribe 9-1/2' RIB and a couple of Kyocera 130's mounted on the davits. The dinghy barely hangs wider than the stern, and will hopefully protect the solar panels if I make any inadvertant "stern-to" landings.

[SilentOption]

This is how I am carrying a 10 foot avon.

I have scraped it along a few pilings already but no there wasn't any damage.
Even though you have it in davits you may still need to bring it on deck if conditions dictate. Understand about not having room ahead of the mast but in a good blow I have even had it on its side lashed to the mast and a few other hard points.