How does your steering seem to be working? just looking at some comparisons and your rudder looks shorter than the one on my boat it might just be the angle of the photo.

Mine is also ridiculously sharp like a knife hence the reason it's covered.

hatches are not on hydraulics. I could have removed them with fair of that rudder wash i get soaking the bildge with salt water.
The rudder that i used is off of Al copelands 46 that did 191 mph. This rudder worked on the same vintage 46 skater as mine.
its 32 inches long and its 6.25 inches below the keels.

How did you determine the angle of attack for the rudder and is it adjustable to any degree?

i really only set the height the angle of attack was designed for al copelands 46 and it worked on his.
i got it as deep as i could. I remember someone telling me the min depth is 5 or 5.5 inches in sbi and or apba rule book.

a lot of guys following this might not know that on shaft drive boats there is no trim like a bravo or 6 you basicaly lower the prop shaft to keep the prop biting the water as the hull gains speed and lifts

there is no trim on any drive that is at the surface other than downward

Here you go: opa-rule-book-2020.pdf

copy of page 87 .... UNLIMITED All Unlimited Class boats must strictly adhere to the following specifications. 1. Hull Specifications: • Hull type: Any * • No. of Engines: Maximum Two (2) • Length minimum: 40' 0” • Length maximum: 52’ 0” • Beam maximum: 12’ - 4” • Tunnel width maximum: 76” • Height minimum: 48” • Weight minimum: 10,500 LBS. ❖ No 3 or 4 point hydroplanes allowed 2. Engine Specifications: • Allowed Engines: Any Piston Driven Engine derived from a “GM” or Mercury Marine Chevrolet type block. Any modifications are allowed to enhance operation in a Maximum RPM marine racing environment. • Engines shall be limited to 6800 RPM Max 3. Transmissions: Single Speed; Multi Speed Transmissions not allowed. 4. Drives: Any 5. Propellers: Cast stainless steel or forged propellers only. No billet, titanium or other type propellers allowed. Note: Minimum blade thickness shall be based on Mercury 1350 propeller specifications. 6. Rudder Specifications: Materials Stainless steel or titanium only Serial number Unique stamped or engraved, required Minimum thickness 0.350”, any fore-aft chord Edges, sharpening Allowed Rudder shape No Restrictions Dimensions No Restrictions Depth Rudder must extend at least 5” below keel @ max lift Trimable Not Allowed Liftable Not Allowed 64 7. Fire Suppression: A minimum of one Coast Guard certified fire extinguisher per engine compartment. Extinguisher must be sized according to Coast Guard regulations.

I can see it better in this photo rudder looks lower than the photo taken from directly behind.
The setup looks pretty much spot on have you tried turning the props in yet to see if the boat performs any better.

Changing the rotation hopefully this coming week. Reshaping the cool air ducts (which were in place before) in order to get EGT's down is the current priority. The stainless exhaust exit tubes have also been raised about 4 inches. (keep in mind the engines were lowered about 3.5 inches in order to keep the drive shaft angles in proper parameters)

Now that drive shafts and shift brakes and crashboxes are out of the way.



i took advantage of the room to get at
the 12 nuts holding on the bpm drives.
spinning the propellers in requires swoping
the drives . Do not swop the wedges like i did the first time. I cought this after starting to
torque down the nuts realizing the wedges are
specific to left and right.... Duh