Are you sure of the spelling? There used to be a firm called Watermota at Abbotskerswell near to Newton Abbot. They marinised Ford engines I believe, but went out of business some years ago.
Assuming the engine in question is fitted to the Nich 35 that you refer to in your other post, it is a Watermoter Seapanther and is rated at thirty something hp, driving through a v-drive. It was based on the dieselisation of a Ford petrol engine.
Spares are available from the address I gave you in the other forum.
Watermota produced marinised versions of three Ford engines. Sea Wolf, Sea Tiger and Sea Panther. They were 1100cc petrol, 1600cc petrol, and a similar size diesel. Watermota were still going in 1997; I have no later data.
The man you want to talk to is Eric Stephenson of Stephenson Marine in Devon. He took over the Watermota business a year or so ago. Nice helpful chap. His phone no. is 01803 814011. I have had Nic 35 no.188 for four years. Probably tempting fate to say this but my Watermota has been just about 100% reliable. If you are Solent area based, I can recommend a first-class engineer who is the area Watermota service agent. Honest, straightforward, reasonable and a nice bloke. Rare bird.