Is it the sea water
pump or the closed system coolant
pump? In any event, if you have a bit of a mechanical inclination you can probably repair the one you have very inexpensively. I'll tell you my experience.
I have a Westerbeke
46 and the sea/raw water pump (this engine
has a heat exchanger) started leaking water. I took it off and took it apart and noticed the seal that prevents the water from entering the oil
part of the engine
on the pump shaft was completely rusted out. I ordered the seal from the Westerbeke representative here in Ontario
and paid $30.00 for it. Once I had the seal I also decided to replace the two bearings on the pump shaft and went to the local bearing dealer and ordered the two bearings. The part number on the old bearings was the same as the new ones and the specs were identical. I paid $6.00 for each bearing. I also asked the guy if they sold seals
and lo and behold he said yes. I showed him my new seal and he took the name of the seal manufacturer (national) and the part number and to my surprise they were $4.00 each, so I bought two more. I ended up rebuilding the pump for $18.00 plus taxes
(not including the rubber impeller). I don't want to even think of the cost of the bearings should I have bought them at the Westerbeke dealer.
P.S. I now have a $ 30.00 spare seal.