Davits

[Pblais]

If I raise my dinghy all the way up, it is 7' up from the waterline. If I had a breaking wave hitting me from the stern at 7' above the water, which is basically eye-level to me standing in the cockpit, I'd probably not be living to tell the tale anyway.

On a tether you probably would be OK but the weight of the waves would rip the dinghy and the arch away in an instant and maybe grab you too with a piece of steel.

On a tether in the cockpit you can probably take more than you think and it wouldn't kill you or the boat. The act of ripping the dinghy away could do great damage to the boat and in the process injure you greatly. No davits with a dinghy can take a the full force of any wave. Davits rated for even 400 pounds can't handle tons of water. If it only tore the boat - OK you lose a dinghy. It might not just take the dinghy that is where the trouble is.

[ssullivan]

Thanks for the input. Someday, when we are able to afford to take the boat somewhere that involves a good offshore leg, I will be sure to get it on deck. Thanks!

[Jentine]

Originally Posted by Pblais

On a tether you probably would be OK but the weight of the waves would rip the dinghy and the arch away in an instant and maybe grab you too with a piece of steel.

On a tether in the cockpit you can probably take more than you think and it wouldn't kill you or the boat. The act of ripping the dinghy away could do great damage to the boat and in the process injure you greatly. No davits with a dinghy can take a the full force of any wave. Davits rated for even 400 pounds can't handle tons of water. If it only tore the boat - OK you lose a dinghy. It might not just take the dinghy that is where the trouble is.

If, as Sully says, the dinghy is 7' above the waterline in his 36' Cat, and the waves are breaking over the stern so as to engulf the dink, the real problem is not the dinghy. It is the faliure of the crew to prepare a sea anchor or drogue or get out of the way of the storm.
I removed my davits and replaced them with an arch. The base of the RIB sits 5' above the water when sailing. I have never had any sea come near the bottom of the dinghy. Granted, I have never been in huge breaking seas from astern, but if I were in that situation, the dinghy placement would be the least of my worries.

[ssullivan]

Originally Posted by Jentine

Granted, I have never been in huge breaking seas from astern, but if I were in that situation, the dinghy placement would be the least of my worries.

Ha ha ha... yes, indeed. That's kind of what I was hinting at. With 7' of clearance on a small boat like this, I'd be demolished by a wave that hit me from astern at that height. That height is the height of the ports and door to enter the salon on the cat from the aft deck. The height is indeed 7' though... I measured before posting.

[Pelagic]

Hi Sean,
Glad to hear you are enjoying the new boat.

I agree with your thinking and believe the main issue in rough conditions is to stop any tender movement which can put shock loads on the davits. That being said, in a survival situation, you don’t want a dingy flailing away above your head, so if I found myself getting into that possible scenario on a long ocean passage, I would strip and deflate the dingy and tie it on deck.

[PBzeer]

One other convenient use for davits beside lifting the dink for security, is keeping it's bottom clean if you stay somewhere for any length of time.

[imagine2frolic]

The previous owner, and co-builder came up with this little crane to get the dink aboard. You can see the crane in the middle of the stern tied to a halyard. The dink sits on a grate nicely, and gets tied off to the boat.

The previous owner sailed the boat from Germany, and I bought it in St. Maarten 3 1/2 years later. The previous owner in 3 years claims everything has always been stable. I myself have closed hauled in 40 knots, and on the quareter with 35 knots. So far no problems....KNOCK ON WOOD

[Donecomutin]

If you want an affordable solution to your davit problem and don't have a very heavy Dinghy then you can try a Dinghy sling which I have been very happy with all last year. It is portable and I have never had the dingy move in the sling even in high waves. Harbormenmarine.com sells these.
I have always been afraid to drill holes in my boat and then see stress cracks in the fiberglass so this was the ticket for me.

[GordMay]

Originally Posted by Donecomutin

... I have always been afraid to drill holes in my boat and then see stress cracks in the fiberglass so this was the ticket for me.

This is a legitimate concern.

Use a counter sink bit to chamfer the shoulders of all holes, to prevent stress risers from causing gellcoat cracking.

Existing cracks can be ameliorated by drilling small holes at the end of each crack. This prevents the cracks from propagating further.

See also some earlier discussions, especially Jeff’s "Primer..":

“A Primer on Fiberglass Construction”: f55/primer-fiberglass-construction-619.html
http://www.cruisersforum.com/forums/...ction-619.html

“Gelcoat Crazing”: /f55/gelcoat-crazing-part-1-a-944.html
http://www.cruisersforum.com/forums/...t-1-a-944.html

“Interior Crazing”: f55/interior-crazing-948.html
http://www.cruisersforum.com/forums/...azing-948.html

“crack repair”: forums/f55/crack-repair-1283.html
http://www.cruisersforum.com/forums/...pair-1283.html

[Aramanta]

Hud absolutely right, we have a SS gantry which started life as davits and then the solar panels, then the wind turbine (got told off for calling it a generator) and then all the aerials.

The rib is kept just below eye level from the cockpit and lashed to the gantry. If I ever get hit from the stern by a big wave it is going to take an awful beating, but the English Channel is not like that - is it .............?

[sluissa]

Unfortunately with my small boat it's practically impossible to put davits on and from what I hear I don't think I even really want any. Plus, they don't really look all that great either, but call me shallow.

[rleslie]

We made our own davits. They are ugly as sin, but work great and only cost $400 to make. The dinghy is on a fixed platform, so it does not swing and we use our mizzen mast to raise/lower the dinghy.

Roger

[Benjamaphone]

Originally Posted by sluissa

Unfortunately with my small boat it's practically impossible to put davits on and from what I hear I don't think I even really want any. Plus, they don't really look all that great either, but call me shallow.

Davits come in many shapes, sizes and intended uses. There are small davits that have a safe-working load of 120 lbs., perfect for a small inflatable. Some davits also have a variety of mounting options that ensure the perfect setup on any sized/type of boat.

As far as aesthetics, there are some davits that are made with a great deal of care in this area. By using cast Almag modular fittings that are bright polished and clear anodized, these davits will maintain their spectacular finish for many years to come. Another way that some quality davit manufacturers produce a beautiful product is by using 316 stainless steel rather than the less-than-marine-grade 304 SS. By using a bright polished 316 SS, some davits may look better than many rails and other fittings already on your boat.

These features, combined with advanced design and functionality, mean that davits can not only be valuable pieces of hardware, but can be a beautiful addition to any boat.

Quality davit manufacturers take these concerns to heart and strive to create a product that meets the demands and aesthetic preferences of sailors.

[rtbates]

My little Cape Dory can't handle all that weight on the stern for sure, but I'm curious as to what an inflatable would weigh full of water. Has no one ever worried about being in a down pour that fills the inflatable back there? Seems like it would be a lot of weight, and in the worse place, even for your big boats.. Covers??

[Benjamaphone]

Originally Posted by rtbates

Covers??

That can become an expensive solution. Always keeping the drain unplugged will prevent this risk. Just be sure to put the plug back in before you go for a ride!

However, people can be forgetful and drains can get clogged. The added weight of water, fuel and gear should be included in your davits safe working load. A davit that is designed to handle every variable will ensure that this will not be a problem.