we'll start the easy way....at the end.

when it's all put together it looks like this - and when you take a picture from the water with a bit of luck it looks like that.

sounds easy ? well pay attention - as I'll be asking questions later.

other than wanting nice pictures - the key drivers here were cost, weight, wide angle lens and remote wireless trigger.

the hardcore pro photo way of approaching mast mounts is to shove a full body SLR camera with housing onto the mast with some sick small lens (17mm or whatever) onto it and let the sailor worry about it. however that's expensive and a real pain to sail with - especially if doing lots of tricky manouvers (shove-it's, back loops etc).

it does have the advantage of easily available remote RF (radiofrequency) triggers but they themselves are also expensive.
I took a standard 35mm compact camera (the Minolta Freedom Zoom Explorer - with a 28mm lens) - which had an infra red remote.
Infra red requires line of sight so I decided to tape the remote to the camera (you can clearly see this in the photo on the left - and solder a pair of wires in order to short circuit the remote from another circuit. (i.e. make it act as though the button was pushed)

The other circuit that I used is a commonly available ($10 cost) Wireless Doorbell. The receiver part of the doorbell circuit was ripped out of its plastic casing and is visible as the big black blob in the bottom of the photo. The plastic black box on the right of the photo is the 6V power supply for the system.

So....looking at the other photo - when the entire system is shoved into a EwaMarine soft case you can see the little blue thing that looks like a doorbell.
well that is a doorbell - you tape it onto the boom - and hit the button when you want the picture taken.

that's it... (the polycarbonate plate with the hose clip connected is the actual mount itself - the camera is tied on with zip-ties)

simple...but effective