Dinghy Davit Dilemma

[GeorgiaSeafarer]

Our new (to us) trawler came with a davit setup that I really don't like. It places too much weight aft past the swim platform.

I am at a loss as to what to replace the current davits with. As you can see there is not enough room for Seawise or Weaver Davits on the swimdeck. The ladder takes up most of the depth of the swim platform. I could possibly place them on the current extensions but I would still be hanging more weight than I want past the swim platform. I am not sure even boom davits would work. Has anyone else encountered this problem and how did you solve it.

 

[HeadedToTexas]

Looks like it better be a pretty light dinghy.

 

[GeorgiaSeafarer]

I wanted to carry our hard dinghy but the ladder is in the way. Even if I could fit Weaver davits, the dinghy would be canted aft. If I mounted the weaver davits on the two arms so the dinghy could cant forward I would have way more weight aft of the swim platform than I am comfortable with. Hard dinghy must weigh north of 100 pounds.

I have ordered an air floor inflatable as an interim fix until I can figure this out. My hope was that I could fit a Portland Pudgy but the more I look at it the less confident I am that it can happen.

 

[koliver]

I wanted to carry our hard dinghy but the ladder is in the way. Even if I could fit Weaver davits, the dinghy would be canted aft. If I mounted the weaver davits on the two arms so the dinghy could cant forward I would have way more weight aft of the swim platform than I am comfortable with. Hard dinghy must weigh north of 100 pounds.

I have ordered an air floor inflatable as an interim fix until I can figure this out. My hope was that I could fit a Portland Pudgy but the more I look at it the less confident I am that it can happen.

This year's trip saw us anchored beside a Commander 30 with a 300# to 400# RIB dinghy, complete with outboard, mounted on a Seawise davit system, modified to push the whole weight aft of a 20hp outboard on a bracket attached to the outboard end of the swim step. Saw it with the extra outboard tilted up so the skeg was just clearing the water, the inflatable hard bottom dinghy was standing vertically, high enough to clear the waves when the Commander was on a plane.

 

[Flatswing]

I’m not clear about your concerns:
Is it that you don’t think the brackets are strong enough? Is your wake hitting the lower portion of the dinghy?
100-150 lbs probably no different than 1 or (perhaps 2) folks standing on the swim platform. Should be plenty strong.
I don’t see your boat size/type, but 100+ lbs. hung low off the stern is usually a non issue in terms of safe handling or performance.

 

[GeorgiaSeafarer]

Flatswing,

My eventual goal is to hang a hard dinghy w/motor off of some boom davits if I can find some that fit.

My short term goal is to make a dinghy available until I can accomplish the above. I just don't have much faith in the davits that are on the boat. I'm probably over thinking things.

Boat is a 35' sundeck trawler

 

[BruceK]

Do the existing "davits" rotate to accept the side tube of the dinghy in the water,and you rotate davit and captive dinghy to vertical using the lines? I bought a set but never fitted them, still in the box. As you say,your difficulty is the narrow swimstep,so the davits are cantilevered off it instead of attached directly. Mine came from Adventure Marine in Canada, adventuremarine.net – Adventure Marine, you could visit their site, they had a video on fitting and use, it might inform and set your concerns to rest, at least for using an inflatable.

 

[GeorgiaSeafarer]

I have no problem with the davits themselves. I don't like them sticking so far back from the swim platform. That extra distance past the platform has to be adding a lot of stress.

The davits work like the weaver davits. The dinghy rotates up into a vertical position.

 

[GeorgiaSeafarer]

There are no videos about davits on adventure marine.net. I believe that I saw a YouTube video on these davits.

Found it:

The video is from Adventure Marine, might be the same one.

 

[BruceK]

There are no videos about davits on adventure marine.net. I believe that I saw a YouTube video on these davits.

Found it:

The video is from Adventure Marine, might be the same one.

That could be what I saw,it`s some time ago. I liked the simplicity but see why the leverage with that mounting is a concern, but it preserves access at the transom. Try the inflatable and see how it goes.
On my current boat I fitted Ceredi snap davits,an unused but 2nd hand inflatable I bought came with Ceredi pads (like Weaver but not interchangeable) professionally fitted.

 

[psneeld]

I have a similar situation. My dingy of around 225 lbs is cantilevered beyond my swim platform where the center of mass is about 6 inches beyond the edge.

I don't fear it being an issue as my swim platform has 5 brackets, each look to easily hold at least 200 pounds and probably 300 easily.

When there is a heavy rain (Florida), the dink fills up with at least several inches of water, maybe more as I usually am not outside in those torrents. No problems with the additional weight before it drains out.

My brackets are on top of the platform and I can't see yours well, but look underneath. My concern there might be tear through of whatever kind of sastener and backing plate might be.

Only you can decide what you feel comfortable with, but often I find many people on here and boaters in general underestimate basic systems unless there are underlying issues like rot, corrosion, etc..... so it is important to have an idea of those issue too.

 

[angus99]

We just finished installing a Dinghy Butler, which is a moderately priced alternative to a conventional powered transom-mounted davit. The DB can be bolted directly to the transom and, assuming you have access inside for backing plates, likely can be designed for a dinghy like you’re talking about with the hinge point sticking further aftward to allow clearance for your ladder when the davit is fully retracted. Dick Shulman, the builder, is very accessible and will have good ideas about solving your problem if you provide him careful measurements.

We did not have access inside under the swim platform and had to install heavy brackets under the platform to support the legs of the Dinghy Butler. Those are vastly stronger than the platform itself. We use a portable boarding ladder to get down to the swim platform when we need to and it takes about 15 seconds to put in position. We lift a ~550-lb hardshell dinghy with ours with no problems. We carry the dinghy about 6 ft above the waterline and tight against the transom which, for us, is ideal.

 

[HeadedToTexas]

Nice! I am currently in the throes of a Dinghy Butler install. How do you deal with the Butler dropping the dinghy well off your swim platform? If you use the quick release, that doesn't seem to be a problem on launch, but retrieval seems to involve a sizable step over open water.

 

[angus99]

Nice! I am currently in the throes of a Dinghy Butler install. How do you deal with the Butler dropping the dinghy well off your swim platform? If you use the quick release, that doesn't seem to be a problem on launch, but retrieval seems to involve a sizable step over open water.

Good question. I wanted the arms to be as tall as possible to keep the dinghy high and dry—which does tend to have the dinghy touch down a little farther aft than desirable. As you noted, the quick release and having a painter in hand as you lower solves the problem when launching.

When returning to the mothership, I tend to put shorter-legged folks on the swim platform before hooking back up to the DB. Once hooked up, I lower the arms enough to leave a little slack in the lifting chains which allows me to pull the dinghy closer to the platform. It’s a pretty easy step for me from there and the lowered DB arm is a very strong grab point for stability. Once we’re up on the sundeck, we remove the boarding ladder—which locks into two keyways—and hoist the dinghy. It’s all very easy once you’ve done it a few times.

 

[HeadedToTexas]

That's what I am hoping for our DB installation. Our's puts the dinghy up level with the bridge deck, but the hinge plates are nearly at the transom gunwale. It occurred to me to build a step into the starboard DB arm to facilitate stepping off the dinghy onto the swim platform.

 

[AZ2Loop]

To the OP, your concern is valid. Perhaps not the overall weight on the mothership, but the stress on the platform itself is what I am talking about. When we purchased our boat, our platform was the original teak platform, designed much like the one Angus pictures above. His looks nice, ours was in rough shape! It had Weaver davits attached to the outer (back) edge of the platform, and that leverage (just as I think you are concerned about) had taken its toll on the swim platform. It was basically crumbling and deteriorated to the point I would not even stand on it unless I was directly over one of the supports. The stress from the davits had proven to be far too much for the teak. We also had a ladder to work around. However, our ladder was only for boarding from the water. From the platform, we enter a cockpit, whereas you climb to the aft deck. That is an additional challenge in the design, for sure.

Our solution: We had 2 new and larger braces fabricated (again, similar to Angus' photos), which gave us 7 braces instead of 5 across the transom. I then built a new fiberglass swim platform, and designed a davit system and had it fabricated. The newly designed and fabricated davit attaches to the front edge of the swim platform (closest to the transom), just above the new braces, on hinged mounting brackets. It works basically the same way as the davit Angus shows above. The 2 new braces are backed with glassed in marine plywood and stainless backing plates inside the transom. It required 4 new holes in the hull (2 for each brace), but all 4 holes are above the water line although the new braces extend below the water line. A new ladder was purchased that mounts under the swim platform and folds up kind of flush to the bottom of the platform when not in use. In full disclosure, I have not yet installed the ladder.

The platform and davits feel very solid and strong, as if I could launch a car off the platform, not just a dinghy. What Angus shows above is a prettier and more elegant looking solution. Ours works about the same way, but not as pretty and probably over built.

My point is the leverage on the back edge of the platform can be an issue. In our case, the platform was simply not designed for that kind of stress and the previous owner seemed to not factor that in. It destroyed the swim platform.

 

[AZ2Loop]

BTW, Headed to Texas, that is a great looking Mariner 37 pilot house!

 

[HeadedToTexas]

BTW, Headed to Texas, that is a great looking Mariner 37 pilot house!

Thank you!

 

[angus99]

To the OP, your concern is valid. Perhaps not the overall weight on the mothership, but the stress on the platform itself is what I am talking about. When we purchased our boat, our platform was the original teak platform, designed much like the one Angus pictures above. His looks nice, ours was in rough shape! It had Weaver davits attached to the outer (back) edge of the platform, and that leverage (just as I think you are concerned about) had taken its toll on the swim platform. It was basically crumbling and deteriorated to the point I would not even stand on it unless I was directly over one of the supports. The stress from the davits had proven to be far too much for the teak. We also had a ladder to work around. However, our ladder was only for boarding from the water. From the platform, we enter a cockpit, whereas you climb to the aft deck. That is an additional challenge in the design, for sure.

Our solution: We had 2 new and larger braces fabricated (again, similar to Angus' photos), which gave us 7 braces instead of 5 across the transom. I then built a new fiberglass swim platform, and designed a davit system and had it fabricated. The newly designed and fabricated davit attaches to the front edge of the swim platform (closest to the transom), just above the new braces, on hinged mounting brackets. It works basically the same way as the davit Angus shows above. The 2 new braces are backed with glassed in marine plywood and stainless backing plates inside the transom. It required 4 new holes in the hull (2 for each brace), but all 4 holes are above the water line although the new braces extend below the water line. A new ladder was purchased that mounts under the swim platform and folds up kind of flush to the bottom of the platform when not in use. In full disclosure, I have not yet installed the ladder.

The platform and davits feel very solid and strong, as if I could launch a car off the platform, not just a dinghy. What Angus shows above is a prettier and more elegant looking solution. Ours works about the same way, but not as pretty and probably over built.

My point is the leverage on the back edge of the platform can be an issue. In our case, the platform was simply not designed for that kind of stress and the previous owner seemed to not factor that in. It destroyed the swim platform.

Thanks for the kind words. Fortunately, none of the previous owners of Stella changed the original crane davit and elevated location for storing the dinghy, so our swim platform was spared. I originally toyed with the idea of mounting the davit on the swim platform but quickly bailed on that. No way was I going to trust a 550-lb dinghy and the dynamic loads that could result from rough seas to a slotted piece of wood.

A friend who is an artist with a welder, built our support brackets (better picture below). They’re made of 1/4” 316L stainless plate and each is attached to the transom with five 3/8” bolts—all above the waterline. I designed them to nest up under the swim platform as tightly as possible and, since the davit bolts directly to these two new brackets, there is zero additional weight on the swim platform.

The backing plates are made of the same stuff and are 50 percent larger than the bracket mounting surface (visible at right in the second pic). As you said, probably overkill but one less thing to lose sleep over.

 

[AZ2Loop]

Nicely done, Angus.

 

[guy with a boat]

Our new (to us) trawler came with a davit setup that I really don't like. It places too much weight aft past the swim platform.

I am at a loss as to what to replace the current davits with. As you can see there is not enough room for Seawise or Weaver Davits on the swimdeck. The ladder takes up most of the depth of the swim platform. I could possibly place them on the current extensions but I would still be hanging more weight than I want past the swim platform. I am not sure even boom davits would work. Has anyone else encountered this problem and how did you solve it.

Maybe this is too obvious to bother suggesting, but you could move or modify the ladder and then tuck the dinghy mounts tight to the transom.

 

[GeorgiaSeafarer]

Maybe this is too obvious to bother suggesting, but you could move or modify the ladder and then tuck the dinghy mounts tight to the transom.

The ladder can't be moved without redoing the sundeck railing. A major project that I'm not interested in doing unless I can't find a better solution.

I'd thought about removing the hand hold on the ladder which would give me the room for a dinghy on boom davits.

 

[angus99]

The ladder can't be moved without redoing the sundeck railing. A major project that I'm not interested in doing unless I can't find a better solution.

I'd thought about removing the hand hold on the ladder which would give me the room for a dinghy on boom davits.

We had the same problem—the original ladder was blocking the davit and preventing it from being fully raised. Finally decided to unbolt the ladder, store it and use a portable boarding ladder. Actually we already had the portable and use it to board the sundeck from either side when we don’t want to bother with the boarding stairs. We just bought an extra set of mounts for the aft boarding gate on the sundeck. We hook it to this set after we launch the dinghy and it’s an easy climb down to the swim platform. Dive n Dog makes ladders with other attachment geometry that might work better on your sloped transom.

 

[GeorgiaSeafarer]

Angus,

I really like your setup. The angle on our transom is a complication. I'm going to have to do some measuring to see what I can do. I've got to check how the ladder is attached. I'm hoping that its not welded.

This boat is brand new to us and there are so many details to check out that my brain is in overload. Plus it's totally different from our last trawler which was more traditional.

 

[timb]

I have the same hoops on my boat . I bought them cheep from a contractor at a boat yard I didn't have any idea who made them .

mine are temporarily mounted with the extensions. on top of the swim platform . they are working great and being mounted on top I haven't drilled any holes or put screws in the platform. I bolted thru the slots in the swim platform and put plates under the platform . it was a $100 test and has been fantastic so far.

the only reason I might change this set up is having to mount the outboard after launch. and not being able to cross my aft lines. I'll look for a picture.

 

[HeadedToTexas]

Very nice. I wish my project was as far along as yours! Where did you tie in the electrical power?

 

[foggysail]

My solution was a davit crane mounted on the bow along with dinghy chocks I made. I easily pickup my ready to launch dinghy and lower it into the water. Takes minutes to uncover the dinghy, set the crane and lower it via button pushing. Retrieving is done in reverse.

Nice not have to screw around removing all the dinghy's contents along with the outboard engine. Oh, my crane operates on 120VAC where I have a choice to use the genny or inverter to power it. My avatar displays the crane raised ready to retrieve the dinghy. Normally it rests lying parallel to the dinghy with the dinghy resting in its chocks.

 

[angus99]

Very nice. I wish my project was as far along as yours! Where did you tie in the electrical power?

Sorry, wasn’t sure if you’re asking me but I’ll prattle on.

The solenoid and wireless receiver are under the starboard set of drawers at left in the berth photo. Plenty of room in there and it abuts the transom. The wiring feeding this gear is #6 duplex from the ER. I put a 50-amp breaker (small yellow lever) near the house bank. One of the remotes stops and starts the winch instantly and I can make precise moves. The other has a lagging response, which I don’t like. You don’t want to over-tighten the winch once the davit is fully raised. It can do serious damage.

 

[HeadedToTexas]

Beautiful work. I had hoped to use a spare breaker on my 12 VDC panel, but the current draw on the winch motor is way too high and an external breaker like your set up sounds like the best approach.

Interesting news about the delay on the remote. I'm guessing that's the key fob remote?

 

[MVDarlin]

I have similar issue on my 44 OA. Whaler with 15 hp OB and center console hangs off the back. I estimate 500# The Oskelly Olafson davit is plenty stout to handle it. To compensate a previous owner added steel bars to the fwd bilge. I have often thought of replacing skiff with with a RIB. I movef a 100 gallon watet qladder to fwd bilge to help compendate