Davits - optimum height above sea level ?

[Loggo]

Strange question I know but is there an optimum height above sea level for a dinghy to be suspended ? The reason I ask is that I am looking at a pair of davits that are straight and would mount about 15 degrees above horizontal from the stern of my Broom 34. Most davits seem to go upwards around 45/50 degrees for a few feet before becoming horizontal which would place my dinghy about 2 m. above sea level.
Anyone got any thoughts ?

 

[NormanB]

Following seas?

 

[rafiki_]

Mine sits on the bathing platform.

 

[oceanfroggie]

Strange question I know but is there an optimum height above sea level for a dinghy to be suspended ? The reason I ask is that I am looking at a pair of davits that are straight and would mount about 15 degrees above horizontal from the stern of my Broom 34. Most davits seem to go upwards around 45/50 degrees for a few feet before becoming horizontal which would place my dinghy about 2 m. above sea level.
Anyone got any thoughts ?

There isn't an optimum height. It depends on the layout of the stern of your vessel. For instance if you have large aft cabin windows/hatches it is nice to have the tender mounted higher so the view is not obscured. Another consideration may be to leave space under the tender for access to bathing platform, etc.

If you had a very large bathing platform you could mount the tender on it with a hoist to drop it in the water. Another advantage of mounting higher is the ability to moor stern in against jetties (i.e. for clearance).

A disadvantage of mounting higher is the stress placed on the davits and transom mounts if you are out in a blow getting a thumping. Typically the angle is about 70deg before the horizontal section.

If your tender/outboard combo is heavy make sure the transom mounts are reinforced internally and also suggest getting davits that have extension bars so that you can strap the tender to the davits rather than just rely on the winch lines when out in a heavy sea. This stops the tender swaying about.

We have a 3.5m rib with 30hp weighing about 150kg on a pair of 175kg Simpson/Cooney with two vertical tubes bracing the davits to the bathing platform. It might seem overkill but we cruise on the Atlantic west coast of Ireland and there is plenty of wind and swell to load the davits underway. If our bathing platform was deeper I'd prefer to mount the tender on it to avoid worry during lumpy passages (eg: F6, or wind against tide in less).

Simpson Cooney davits are popular on aft cabin vessels like Broom, Atlantic, etc

Reinforcing tubes to brace davits

BTW, our davits are motorised because we anchor out a lot so our tender is up and down like a yo-yo, and I have a bad back.

 

[Sandrena]

Strange question I know but is there an optimum height above sea level for a dinghy to be suspended ? ...Anyone got any thoughts ?

Depends on the height of tide.

 

[Greg2]

Strange question I know but is there an optimum height above sea level for a dinghy to be suspended ? The reason I ask is that I am looking at a pair of davits that are straight and would mount about 15 degrees above horizontal from the stern of my Broom 34. Most davits seem to go upwards around 45/50 degrees for a few feet before becoming horizontal which would place my dinghy about 2 m. above sea level.
Anyone got any thoughts ?

From what you are describing I would question whether the bottom/keel of the dinghy would be 2m above sea level on a Broom 34. Not that I think it matters because I think it would be absolutely fine. Some have chocks on the bathing platform with the dinghy overhanging the water so only a couple of feet clear and you would have way more than that. As already said having belly bands and a means of reducing/stopping side to side movement would be good. We have belly bands fitted all the time and if we go on a longer sea passage I use ratchet straps (stainless steel type) to secure each end of the RIB to the opposite davit.

 

[Loggo]

Thanks for the thoughts - especially Ocean Froggie who went above and beyond ! Currently the dinghy (2.8m and 3.3hp outboard so not a Great weight) lives on edge on the bathing platform. I have two straps that pass underneath the dinghy allowing it to be raised single handedly. The main benefit of the davits would be to allow the outboard to be left in position.

 

[Bandit]

The other alternative is Snap Davits.

You have to remove the outboard (I stow mine on a bracket on the swim platform).

The dinghy has a clip glued to the tube and one on the swim platform and the dingy stows vertically.

Much cheaper to buy and fit.

One advantage is the overall length of the boat is less so lower mooring fees.

These are much cheaper than full davits