Thank you Jim and Sailing Dog. The thing is it could well be sitting at the bottom of my dock/slip. The last time I went out it got me home just fine.
So perhaps with the low tides when the boat sank down into the mud it worked it's way off.
Jim asks whether it was an expensive prop. I don't know. Came with the boat last year when I bought it. Guess I'll find out. Regarding zincs. I don't know where to look.
I'll let you know what happens. Guess I am in the market for mask and flippers.