Boss Lady Renovation

[Boss Lady]

I talked with Tom Slane at Slane marine about the increased speed with this hull design. He told me that some people have had problems with keel walking due to the keel acting like a hydrofoil, we don't think this will be a problem because the keel is not flat, but more U shaped on Boss Lady. Some boats have very flat bottom keel surface which acts like an underwater ski and lifts the boat and causes chine walking. Some people have tried to remedy this by cuttting down the keel. This still did not solve the problem on a couple of boats, because they just made the keel shorter but left the same profile. What they should have done is shape the keel to more of a knife edge to eliminate/kill the lifting surface. We can react to any handling problems that come up. Not every shop understands the hydro-dynamic forces at work, I have seen some pretty scary solutions from the "let's see what this does" crowd.

The 10 knots increase mentioned is probably correct, but the 16 knots speed was based on a very gnarly hull surface (lots of drag), very tired engines, and the rudder linkage rod was discovered to be 2 inches too short so that the rudders were toed in about 15 degrees each creating a hell of a lot of drag, and it had the wrong props on it. If we derate the engine HP from 330 to 250 allowing for poor engine performance we almost triple the horsepower with new engines, Plus we have to add in the efficiency added by the lift rails. There are still a lot of variables, but we think we have been conservative in our estimations and performance expectations. My goal is a 25 knot cruise.

The previous owner did tell me that one rudder was replaced after he struck a coral head navigating a narrow pass in the bahamas, what he didn't tell me was that the couldn't get a replacement linkage rod so they cut off the stripped threads and rethreaded it, and he never replaced it, hence it was 2 inches too short.

[Avenger]

Just FYI, I did the math based on the 330 HP rating, which says you should have been doing about 18 kts. With the 735 HP rating the math says 28.5 kts. So you should be okay for your 25 kt. cruise. I assumed that either lower HP or other factors were robbing you of the 2 kts. in your current configuration, and if the "other factors" weren't fixed it would rob you of them with the new power too. There are many variables the the formula doesn't cover, but it's a decent guide. Hope the variables work in your favor.

[Boss Lady]

Thanks for the help! There will be new pictures posted as the project moves on. There are some good pictures of the lift rails being constructed. We used Divincel foam and glassed it in. We used 6" wide 24 oz (style 1808) to layup the rails. Look under projects at www.starcarpentry.com

[Traveler 45C]

I had a look for the first time on your project, WOW! They really did take her down, didn't they? I can't imagine my boat taken down that far.

Good luck! You surely will have a NEW boat when your finished.

I'll be giving you that call tomorrow...