I have a F115 Yamaha that has about 250 hrs. When I purchased the boat, I had a water pressure gage installed on the dash. I watch it carefully and the gage has not shown any drop in water pressure at a given RPM . I know Yamaha recommend inspection and replacement as need of the water pump at 200hrs but my question is ---- does the pressure gage provide a reliable measure of water pump wear ? My gut feel is that if you pay for the inspection you might as well go ahead with a replacement . My theory when the I bought the boat was that if I watched the water pressure I would be able to spot a drop in water pump performance and have it replace before it failed. Now I am not so sure I was correct since I have seen several reports on these boards of catastrophic water pump failure. Any recommendations ?