On the subject of CCTV.........the marina has two cameras which might be relevant.
One is at the top of the ramp leading down to the pontoons and one is at the corner of the dry-stand area, next to the toilet block. Both might have captured some images. Check with Mike or the Harbour office in Douglas.
However when I had my "incident" (b****d WAFI's yacht fell on my console smashing it and doing £7k's worth of damage) they informed me that the CCTV coverage would only be released to the police (if crimed) or to your insurance company who were threatening legal action.
"Ribbing-the most expensive way of traveling third class"