What is it

[martinchambers]

We have this fitting on the cabin top under the dodger, next to the halyard winch, port side. The hole is 48mm and about 70 deep, with two 6mm pins in the bottom as if to lock/locate something. Can anyone tell me what it is for. Picture attached.
Yacht is a 2002 bavaria 47 oceans cc

[IslandAlchemy]

Is it a socket for an outboard engine hoist to sit into?

[Yngmar]

Proximity to the winch is a hint, I think. Too close to be for a removable chartplotter, my bet is it was a fixing socket for an electric winch handle (to avoid having to hold it by hand). Size and distance from winch look about right for that. As does the fact that it's near the halyard winch, which is always the first to be electrified

In case you're not familiar, these are made commercially (Winchrite, eWincher) and also DIY by converting various powertools with a winch socket.

[martinchambers]

yes, i thought an electric winch fitting, but cant find one that fits. I also couldn't understand how the halyard could be then led into the winch, unless you put the rope on first, then install the unit. Might as well go hand held like eWincher then? Is there anyone who can give me a model or make that might fit so I can investigate further?

[IslandAlchemy]

https://www.plastimo.com/en/mooring-tenders/davits-cargo-booms/embases-de-rechange-pour-bossoirs.html

https://www.floatyourboat.co.uk/stainless-steel-davits-single-or-pair

[Yngmar]

The common DIY one consists of an angle drill with a winch socket adapter. They can be either powered by battery pack or with a long cable so it can be used around the cockpit in different winches.

Same as the commercially available ones, they are inserted after the rope is put on the winch. Then you need one hand to hold the handle against the torque generated. As this may be inconvenient, it's also possible to make a mount for the rear end of the powered handle so it can be used without needing to hold it. I expect that's what that socket is for.

Perhaps the previous owner didn't want to give up his angle drill and so it wasn't included with the boat

This one is from a mountaineering rescue system, but using a standard sailboat winch and illustrates what I mean pretty well (although they didn't do a nice stainless steel job for the holder):

[martinchambers]

It is certainly not a davit or lifting point. Centre cockpit under dodger.
Power winch could be it, but all the ones and indeed a side drill are hand held. This is a commercial fitting so if it is for winch power there must be a model out there it is made for. Does anyone have an idea?

[Yngmar]

It's just a stainless fitting - you can buy those for any number of things, table legs, fishing rod holders, davits, etc. - then repurpose them as needed