I built a really simple clew mount out pvc pipe. Hose clamp it to the boom, and use a RAM mount on the end for the camera. Camera is about 2 feet aft of the boom end, angled down for good footage. You see the horizon, the sailor, and the foil under the stern. Easy peasy. Not as good as a drone, but a heckuva lot cheaper.
Here is an old video I made that shows how it looks: