Originally Posted by Chris Sunkin (Post 1989126)

You're right in wanting to know how your boat performs in differing conditions. You've hit on a common issue- someone moving from a highly maneuverable boat and into an "offshore" style boat. Offshore boats are made for hammering waves straight on- that means compromises in turning. Adding to this issue is the stepped hull of your boat. First, your Donzi wasn't designed to "carve water" and the physical stresses of doing so and exponential vs. a ski boat. That being said, 30 or 35 mph isn't fast- unless you want to do full-lock, full power turns at that speed. Second, stepped hulls need to be turned in the proper procedure. If your wife might go off with a boat acting "weird", think of what she'll do after getting the experience of a high-side ejection from the boat. I can't give you specifics on your boat but most steps like to be settlled then powered through turns. I'd suggest hitting one of the Donzi forums and getting with some folks who own your specific boat. I don't mean to scare you but more than a few experienced racers have been tossed in turns from not cornering properly. Also, my step-V experience isn't near what many on here have so they may be a better source of specifics. My only experiences have been a few turns at the wheel and one trip as an eject-ee.

On Tres' school- it's probably a tremendous idea but I also think alot of it might be lost on a newer perf boater. It's sort of an MBA in high speed. No one says you can't go back for a second trip, though.

To your question on tab position- you'll want to use the drives to control nose up/down. Tabs are more for yaw- if you're getting cross wind and it's sterring you off-course, drop the opposite tab and straighten the boat up. Some boats need a touch of tab at neutral drive position especially running into a head wind. You'd probably want to keep your tabs neutral when turning. Tabs will give you a little more "effective bottom" basically adding a small amount of bottom running surface to your boat. There are times that you can get better top speed by trimming out until you lose lift (bow porpoising) and tab it down just a little bit. Sometimes youll do better like this rather than neutral tabs and less drive trim- but that's really dependent on your specific boat and load- that's the fun of experimentation.

Originally Posted by Dude! Sweet! (Post 1989555)

Just did a search on Amazon.com to get the book. I got it used from someplace back east for about $30.

Originally Posted by Chris Sunkin (Post 1989229)

You can trim to where you porpoise or where you lose speed. You can trim it to where you lose stability or at least start to feel like it's going away. If you're going from neutral to rooster tail and not seeing a climb in speed or rpm, there's a problem. I don't recall the Baja having an over-conservative x-dimension so you may be in need of a better prop.

No drive is really designed to intentionally throw a roostertail. Surface drives just do but that's irrelevant here. Unless you're dealing with big power, throwing water into the air is likely more counter-productive than anything. Lots of performance boats have Bravos on them. They're actually faster than the TRS they eventually replaced but a bit less durable as you near max power. They are usually mounted at a decent x-dimension and typically uitlize a cleaver prop. That means that they can be trimmed up until just the bottom of the prop engages the water and the top actually comes out as it rotates. That's where you'll find the least amount of drag and the highest efficiency.

Someone smarter that I will have to explain how different prop designs and dimensions affect bow and stern lift and how to properly size a prop to a specific boat. It's a little science and alot of art.

Originally Posted by blacktruck (Post 1991359)

"typically utilize a cleaver prop" That would be the last prop to use on a bravo especially on that guys baja. Cleavers are best used on outboards that are mounted very high on lighter hulls (generally), not on heavier sterndrives. I would listen to Tres when it comes to learning about high performance boating safety.

Originally Posted by marylandmark (Post 1989950)

Confused.. Wouldn't this set me up for a stuff?


(asking, not flaming..)