Sorry to hear that Mark, what pontoon are you on, i was working there all last weekend on a couple of different pontoons, might be lucky and i may have seen someone, although do not recall seeing anything at the time
What about all the cameras and number plate recognition system? I guess you have contacted the office?
I suppose all we can learn is to mark the canopy in a secret way and then if it’s stolen and spotted later on you can prove its yours. No help to you unfortunately.
Are there any more V40/42 in the marina as another owner may have requested a new canopy or repair etc from a canopy firm, the firm quite innocently may have removed the canopy from your boat thinking they have the right boat perhaps they were a bit lazy that day, seen your boat and presumed thats there client, just a thought.