Thanks, OJ! Nice to hear from you. Actually, I've already bought a Vetus bow-thruster. As you mentioned, it was pretty tricky locating it. We have cut the hole through the bow, and we have fit the tunnel. We do have a little more than one tunnel diameter between the top of the tunnel and the waterline. I had to put a lot of thought into the installation, because I had to remove a significant amount of the hull liner, and most of the wood within the little seat/step in the vee-berth area. However, I've managed to not disturb any of the woodwork/cabinetry that is visible when everything is in place. I believe that it's going to work out so that I could actually reinstall the water tank that I've removed to provide access for this installation. However, I will wait until the boat is floating to decide whether or not to install the water tank. I'm leaving that and some of the battery placement issues until I see how she floats on her lines. It's difficult (but not impossible) to figure if I've made the bow heavier or lighter. I'm adding an electric anchor windlass, a bow thruster and a forward battery, all of which adds weight forward, but I've eliminated a lot of heavy hull-liner and a big water tank, all of which reduces weight forward. I believe I'll fill that tank, weigh it, and also weigh the stuff I've removed. That will give me some idea....
Rich,
No, unfortunately that beautiful photo will not provide the engineering info I need. However, it's a very inspiring photo!
Neil, my "stealth" bow-thruster is going to be my little secret. Nobody will hear it!
However, since you mentioned a bow-thruster app, I will point out that there is actually a smartphone app that will control this thruster via Bluetooth. Not that I would ever use it.....
OK, I'm still hoping somebody will help me figure out this angle thing. The Vetus instructions suggest that the optimum (minimum drag) installation requires a hull fairing on the aft side of the tunnel, and that this fairing should be installed in line with the expected bow wave at the tunnel location; I'm assuming at hull speed, since that's when we want to be least limited. Obviously this calculated angle will be close to correct only when the yacht is sailing level or under power, but it will help in any case. Vetus obviously put a lot of research into this plan. I've had it checked out by a professor who understands these things, but I forgot to ask him how to calculate the angle. I do plan to ask him this question, but I'm hoping that the good folks on this board will give me a heads-up so I won't seem SO ignorant when I ask him. The instructions mention a maximum of 15 degrees, but if they've included a way to calculate exactly what the angle should be, I can't find it.
