Bottom "Truing"

[boatnut]

I'm reading lots of information about repowering Donzi classics, classic hull design, props, etc.
This is all of great interest as we are considering repowering a '69 18. What I haven't seen any discussion on (maybe there has been some as I am fairly new to the forum) is the subject of truing the bottom of these classics when you want ultimate performance. I have checked 3 or 4 Donzis of various ages, and (using a staight edge on only a short section forward of the transom) have seen varying amounts of hook and once even a little rocker on these boats. My experience (admittantly on non-Donzi hulls) has been that if you really want the ultimate in performance you turn the boat over and "true" the bottom. Using a large (4+ feet) straight edge, you fill/grind/sand all hook out of the hull and strive for a staight running surface. You then can control this running surface with the various afterplane products on the market knowing the bottom is true to start with. My question, is this worthwhile for ultimate 18 performance?
I'm not sure what Donze strives for (in the way of hook/rocker) but I assume some slight hook is desired?? I do know that this will change over time depending on how long the hull is allowed to originally cure in the mold (sometimes not enough in a production envirnonment) and even is effected by incorrect trailer bunks etc. Your comments would be appreciated.

[MOP]

Do a search on Hook and rocker there have been a few discussions that may help. It also to a point depends on how fast you want to get the boat unless severe alot of people would not know the difference. CDMA can give you very good info he is our in house hydrodynamic Garu!

[boatnut]

Does anyone know what amount of hook or ??? Donzi strives for when building an 18 Classic hull? Ed

[BillG]

Why would you want hook in the bottom unless the boat won't get it's butt up. Rocker is the way to go in a normal boat. 16's have some hook on the chine but I don't think there is any on the bottom. You can control rocker with tabs but hook is there to stay.
Bill G

[MOP]

All the 16's I have seen were dead flat on the keel, with a little hook out board.

[Rootsy]

i have a 16 and i've looked the bottom over pretty thoroughly in my quest for excessive speed... the hook starts at the chine and goes to the first (outer) strake and then from that point to the keel it is straight...

is it true that the only really rockered donzi hull is the factory Blackhawk boats?

[Scott Pearson]

I have Hook and Rocker in my 1967 Bench Seat Hornet....Its not a Blackhawk...thats for sure.


(NJ)Scott

[McGary911]

I have Hook and Rocker in my 1967 Bench Seat Hornet Scott, that's interesting....Rocker to the chine, and hook near the keel??? Sounds pretty cool....