Dingy Davit Horizontle Stabilizer

Sep 27, 2008
185
Hunter 41 Longport,NJ
Hi all - I am going to brave putting this together for my Kato Marine Davits on my Hunter 41. It will carry an AB AL aluminum bottom dingy and maybe, just maybe a Yamaha 9.9 outboard The question is, how far apart from each other should each of the Davit arms bet be fixed? I read that the lift points should be 6-12 inches inward from each hoist point to form a trapezoid and allow the dingy to be held vey high. My question is - how should I position these if I am using a dingy sling - which of course creates extra space between the davit and dingy lift points. Any suggestions appreciated
 
Feb 10, 2004
3,917
Hunter 40.5 Warwick, RI
This is a project that looks simple but is anything but simple. I am not sure how a dinghy sling would work- for instance, what keeps the sling from moving under the hull?
I have a conventional Achilles dinghy and I mounted two eye bolts thru the transom near the floor and I glued two "D" rings to the inside of the bow. I mounted my davits and swung them inward toward each other to get the inward distance from the hoist points that you describe. A brace was attached to the davit arms so that they could not move.
I tied a bridle between the stern eye bolts and another one between the bow "D" rings and adjusted the length of the bridle lines so that when lifted the dinghy tipped to the side with a drain. I hoist the dinghy with the bow higher than the stern so that rain water would always drain out.
One challenge was to adjust the bridle so that the hoist hardware did not rub against the outboard or the bow tubes. Sounds easy, but it took me hours of testing configurations to get a working plan.
Finally I added four straps from each "corner" of the dinghy to the davits to prevent any movement and chafe. The davits and the dinghy are nearly a solid unit.
Take a look at the attached pix for the details I have described.

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Sep 27, 2008
185
Hunter 41 Longport,NJ
very helpful - appreciate the pictures - looks like a long weekend of experimentation
 

Tom J

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Sep 30, 2008
2,301
Catalina 310 Quincy, MA
looks like a long weekend of experimentation
Yes, but worth it. Like Rich said, the bow must be higher than the stern, and the dinghy must be tight to the davits in all directions. It took me a few tries to get it right, but now launching and retrieving the dinghy is fairly quick and simple.
 
Sep 27, 2008
185
Hunter 41 Longport,NJ
Hi - Thanks for the inputs - gave it a shot this weekend - and seems ok. Pics attached and thanks for all the help - only problem I have is that the outboard is mounted onto the stern rails and prevents the dingy coming up all the way.

So I either have to keep that heavy Yamaha 9.9 (on the left under a cover) on the dingy, or secure the dingy under it strapped tight to the stern - more experimenting to do ! Thanks all
 

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Feb 10, 2004
3,917
Hunter 40.5 Warwick, RI
If it were me I would want to keep the outboard mounted to the dinghy for ease of launch and readiness. If it is a 4 cycle, it is probably heavy but perhaps that is all the more reason to keep it mounted on the dinghy. Even a 2-cycle is a handful to hold and mount without dropping it in the drink.
 

capta

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Jun 4, 2009
4,766
Pearson 530 Admiralty Bay, Bequia SVG
We use a pair of sailing dinghy main sheet block and tackles crossed like fore and aft spring lines to keep out inflatable from swinging side to side. One block has a V shaped groove to secure the block and tackles tightly making them simple to tighten and release.
The hardest part is finding a place to attach each end without any chafing. We had eyes welded to the davits in the eventuality that we might need them, and we did. We lift the dinghy w/the 15 hp 4 stroke OB in place on the dink Haven't had to clean our inflatable's bottom in years!.
 
Sep 27, 2008
185
Hunter 41 Longport,NJ
Thanks guys - will try leaving it on see how it goes I think the davits are rated at about 300 lbs or so each - so should be able to handle it, as long as I'm not sitting in it (joke)
 

Tom J

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Sep 30, 2008
2,301
Catalina 310 Quincy, MA
Hi - Thanks for the inputs - gave it a shot this weekend - and seems ok. Pics attached and thanks for all the help - only problem I have is that the outboard is mounted onto the stern rails and prevents the dingy coming up all the way.

So I either have to keep that heavy Yamaha 9.9 (on the left under a cover) on the dingy, or secure the dingy under it strapped tight to the stern - more experimenting to do ! Thanks all
You really want that dinghy mounted as high as possible, preferably tight to the bend in the davits. Limiting the vertical lift leads as much as you can will limit how much the dinghy will sway. I like to tie the bow and stern lines of the dinghy to opposing davits, and then run a line from the outside of the stern of the dinghy to a low point on the big boat's stern, to keep the dinghy from jumping up. In a confused sea, the dinghy will want to bounce around, and will impose shock loads on the davits.
Do you NEED a 9.9hp outboard? Maybe a 5hp would serve to get the dinghy where she needs to be, although without the joy of planing. A smaller outboard might fit between the bow of the dinghy and the davit when the dinghy is lifted all the way up. And I think the first time you carry the outboard into the dinghy while it is bouncing a foot up and a foot down, even in the lee of the big boat, you would be glad for a smaller engine.
 
Sep 27, 2008
185
Hunter 41 Longport,NJ
You really want that dinghy mounted as high as possible, preferably tight to the bend in the davits. Limiting the vertical lift leads as much as you can will limit how much the dinghy will sway. I like to tie the bow and stern lines of the dinghy to opposing davits, and then run a line from the outside of the stern of the dinghy to a low point on the big boat's stern, to keep the dinghy from jumping up. In a confused sea, the dinghy will want to bounce around, and will impose shock loads on the davits.
Do you NEED a 9.9hp outboard? Maybe a 5hp would serve to get the dinghy where she needs to be, although without the joy of planing. A smaller outboard might fit between the bow of the dinghy and the davit when the dinghy is lifted all the way up. And I think the first time you carry the outboard into the dinghy while it is bouncing a foot up and a foot down, even in the lee of the big boat, you would be glad for a smaller engine.
Really good point on the 9.9 It's almost brand new - maybe I can get a reasonable price for it - was thinking about getting rid of the AL-10 for a lighter dingy, maybe with an inflatable floor and a much smaller outboard
 
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