Inflatable Davit system thoughts

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Ken34

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OK,a quick preface. I currently use a weaver system and place my OB on the boat. this is a very easy process as I have a Nissan 9.8 and the weight is minimal at best. Its a very easy moyor to handle. I contemplating going to a bigger motor as I think I would like to purchase a 4 stroke 15 for a little more torque on the low end. I just know I will not be taking this on and off like I do now.

With that being said, I do not want a Hurley set up because I want to keep the platform free of obstruction. This is the same for a La Croix type system.

I have mocked up a plan that would add two reese type receivers (like a trailer hitch)under the platform. I would then have two individual arms that extended past the platform with a craddle on each arm. The loading side would have a roller to assist in loading and launching. I would obviously use tie downs to hold the zodiac in place.

I would then have 2 individual arms I could store away in the bilge and have the platform free of obstruction for the dog and soon to be baby swimmer.

Anybody out there have any such system that I could possible see pictures of for a rough idea if I am on the right train of thought?

Any thoughts?

I can post a pic tomorrow of what I am thinking of.
Thanks
Ken
 
post photo. Note there are removable weaver style davits that leave just a slight protrusion when removed. I get concerned about the forces when the dinghy weight is beyond the end of the platform. You will need a backing plate on the top of the platform as all the weight is on the bolt heads if mounted below. Over all though it should work. I think something similar has been tried. Make sure that dinghy is not going to hit the water going on plane.
 
The Freedom Lift would be great, but its a bit to rich for my blood!
 
Disregard the bunks spanning from each arm. I understand I will have to add extra support to the area it is mounted on the platform.

Platform.jpg
 
I'd be worried about the strain on the transom. We had a video a year or so ago of some million-dollar yacht sinking; it was believed the swim platform came loose. Wasn't pretty.

I know MY transom couldn't handle it without a LOT of reinforcement.
 
Interesting idea. I'm no engineer, but I would imagine the swim grid would need to be significantly reinforced from a structural standpoint to handle that much additional weight, especially with the cantilevered system the proposal shows. Perhaps another set of receivers, or longer ones, and longer arms?

Also, would such an arrangement place the dinghy too low to the water for adequate planing (even when properly trimmed)? How would the boat carrying the dinghy that low perform in larger following seas?

If you could get the dinghy up higher, perhaps with L-shaped arms that bend 90º to vertical?
 
quote:
Originally posted by Woodsong

Neal did a similar thing for his meridian but utilized the weaver snap davit bases:
http://www.boatered.com/forum/topic.asp?TOPIC_ID=147141

Click to expand...


Ken

I used the system above all summer and it worked great. You can cut the support arms in any shape to best suit your dinghy and mother ship. My swim platform was already almost 2' above the water line so I cut my cradle supports long enough to reach the water line and allow the dinghy to slide up the supports without much trouble. My entire dinghy rig weighs about 400 lbs. and my boat never hesitates to jump on plane, I never even feel the dinghy. Recently I was in some heavy following seas and the dinghy would hit the water occasionally but with no harm. I installed eye bolts on both sides of the dinghy transom and ratchet strap the dingy down to the swim platform and also use longer ratchet straps from the swim platform cleats crisscrossed under the dinghy and secured to the bridge. Let me know if you want more info.
 
Ken could you resize the photo a bit smaller so the slide bar goes away? Kinda tough to follow the thread.

As far as extending the dink out beyong the platform goes, I say you've got to study the platform to see if it can support the extra leverage. It was designed to support some amount of weight within a certain distance from the transom. If you take that weight out beyond the edge of the platform you have to think about all of those forces, and those that are localised to the area surrounding the contact point between the system and the bottom of the transom.
It's not just the local forces at the junction, it's the forces at the point the platform joins the transom and the leverage will aggravate those points of contact.

My 2 cents.
 
I had a very similar issue and I went with St. Croix Davits. They came up with a very workable solution and their quality is superior. Customer service is even better. Good luck.
 
quote:
Originally posted by Ken34

OK,a quick preface. I currently use a weaver system and place my OB on the boat. this is a very easy process as I have a Nissan 9.8 and the weight is minimal at best. Its a very easy moyor to handle. I contemplating going to a bigger motor as I think I would like to purchase a 4 stroke 15 for a little more torque on the low end. I just know I will not be taking this on and off like I do now.

With that being said, I do not want a Hurley set up because I want to keep the platform free of obstruction. This is the same for a La Croix type system.

I have mocked up a plan that would add two reese type receivers (like a trailer hitch)under the platform. I would then have two individual arms that extended past the platform with a craddle on each arm. The loading side would have a roller to assist in loading and launching. I would obviously use tie downs to hold the zodiac in place.

I would then have 2 individual arms I could store away in the bilge and have the platform free of obstruction for the dog and soon to be baby swimmer.

Anybody out there have any such system that I could possible see pictures of for a rough idea if I am on the right train of thought?

Any thoughts?

I can post a pic tomorrow of what I am thinking of.
Thanks
Ken

Click to expand...


Sorry for late response; took a while for account activation...

You might like to check Jatco Marine's Trillogy Lift. (The spelling is correct; their marine engineer is Joe Trillo.)

The system actually looks similar to your drawing, and much of it can be removed relatively easily... although there are still four attachment points on top of the swim platform that remain. The dinghy loads from one side or the other (you choose).

FWIW, our current dinghy is a Walker Bay Genesis 10.2 (135-lbs) with a 5-hp 2-stroke outboard (46-lbs)... and I'm contemplating a larger engine whenever I get a round tuit. We've got the basic Trillogy system but also with additional support struts added that are attached directly to the transom, underwater. That slighly limits how much of the system can be removed while in the water, but the remaining parts haven't been in the way for fishing. In that current configuration, I think the lift is rated to something like 450-lbs load or maybe more.

The stern-mount system (as with any) still comes with pros and cons, of course.

Happy to answer questions if that would help.

-Chris
 
Good info.

I will definitly place it in the thought process.

Thanks
Ken
 
This is my Forespar folding davit system.
I am too old to be lifting 110 pounds of motor on and off the dink.
They lock in place to hold the dink and whwn you remove one pin they fold
against the transom.
I used stainless grab handles to attach to the transom with backing instead of
direct attachment so that I can remove the davit and only have two grab handles
which are always handy on a platform.
The port davit will also swing out over the water as a crane to take my motor on
and off the boat. two bolts and four pins removes it completely for winter.

HPIM0945.jpg


HPIM0944.jpg
 
I will be adding two Supports to the bottom of the mounts. I mocked everything up. I plan to use starboard v bunks and I do not see a need for a roller. It slides up and down very easily. I placed the lines around there for temporary stability while underway. I think I may be happy with this system
 
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