A good clean bottom

[Chimo]

Every 6 months I haul the boat and change zincs. I just do a half haul, leaving the boat in the slings for about an hour or so while the crew go for lunch. It's inexpensive. Normally there is next to no growth on the bottom as I have the boat in a boathouse but I get them to clean off the stern where light has come under the curtain and growth has happened. This year I have been hanging a tarp off the stern to block that light and the result has been very noticeable. To check the effect over the longer term I asked them to give the whole bottom a light wash off to give me a starting point. As a bit more of an experiment I took the boat out and measure WOT before and after. Not a great difference with 2960/2970 beforehand and 3000/3020 afterward but a good comparison with the same load on the boat. I just thought others might like to see the numbers. Photos are in the album. Ignore speed because tide changes play a big role.

 

[BB marine]

Not a big difference but still the growth accounts for additional load. It sounds as if the growth was minimal to start with. It looks like your max RPM is right in line with Volvo. I'm impressed with your performance numbers. I didn't realize that the R25 would make 16 kt. and a cruise speed of 14kt. Very nice!