Hull Blueprinting
 

I've been playing with the idea of doing some work on the hull of my boat for about four years now. Looking at the recent article in Family and Performance Boating, got me thinking again. Years back, I noticed a hook in the bottom, and was wondering if taking it out would help performance. According to the magazine's article, they removed a 1/8" hook, and picked up 4 mph. I have a similar hull, and I think my hook is more pronounced than that. Any thoughts on this? I'm thinking about doing this near the end of next season. If it's worth it.
I don't know if this is something I want to do myself though. Anyone know a good glass guy on Long Island?

Leon took the hook out of a 32 sunsation named dragon heart and it picked up 4 to 5 mph, he's not local but it's Derebery performance, pottsboro Tx 903-786 3797. i'm sure someone in your area can handle a job like that for you, maybe some one around here's know's who
mark

I think it's the right thing to do. I wonder what something like this would cost?

a blueprint on hull to get the hook out will cost more if you want a final finish of gelcoat instead of bottom paint, most of the time they charge by the foot. i'm not sure what the going rate is, but it sounds like an easy speed increase without going into the motor

My boat is bottom painted, so I don't need a high gloss finish. According to the article in Family and Performance Boating magazine, the place up in Maine that did their 24' Scarab would have charged $550.00 for the work they did. That included a glossy gelcoat finish. I wonder if that would be a good ball park figure to go by. I'm in NY, nothing is cheap here!

My 32' Active Thunder had a hook in the hull. I had a shop remove the hook from about the last 3-4 feet back to the transom. He sharpened the strakes and the edge where the tansom and bottom meet. Using my GPS, at 4000rpm I went from 64.5mph to 69.5mph. I haven't been able to conduct a fair top-end comparison yet. I would guess that it would be about the same gains...4-5mph.

Marty Bowker did my hull. He's located in Holland, MI. Holland is right on the shoreline of Lake Michigan. He can be reached at: Bowker Fiberglass (616) 218-1683

Could you give me a ball park as to what this cost you?

I just now paid the bill for my hull repairs and blue printing the bottom. Lots of work on chine repairs to the "old Sonic".
Total cost was 1000.00 for the repairs and blue printing with a total new gelcoat bottom for a 31 foot boat. Hope that helps....

I had mine done a few years ago. Unfortunately, the net gain was zero. you have to consider how good the bottom is to start with. Mine it appears was very good. Cost was less than 1k. They only work on the wetted surface when the boat is on plane. So even on a long boat, it is only a certain percentage of the hull bottom. There have been other cases where people have picked up 4-5 MPH.

Does anyone know of someone we can trust in the NY/CT area to do this work?
An old repair has shown up on the hull(paint peeled) since the boat has been out of the water, and I'd like to regelcoat the entire bottom.

I just came back from the boat yard. I went up with a straight edge, and a blanket! Seems the hull is in better shape than I thought. The only place I can find any hook is all the way out by the port strake about 8 inches from the port edge of the hull. It's only in a small area. This I could probably do myself, but I probably won't see any gain. The only other thing I'll do is clean up the pad area. There are some scratches and things that need to be addressed. Are there any other things I can do to the bottom to help it along?
One other thing. Ever since I got the boat, I noticed a little rooster tail coming off the port side of the drive. At speed the water seems to kick off the anti ventilation plate, and make this little rooster tail. The drive has no nicks or dents anywhere, and it didn't change when adding the nosecone. The starboard side has always had nice flow. The hull in that area is clean and flat. This one has always stumped me.:confused:

The "rooster tail" could have to do with the steel braided trim lines.

An easy thing to do is sharpen the strakes and the transom. Water is sticky, and if you have sharp edges it will cut thru better and it won't stick to the transom edge.

Good idea with sharpening the edges. I've seen a number of people saying they did that. I'll give that a try.
Ric, as far as the trim cylinder lines go, when I'm running at speed, none of that is anywhere near the water. The only thing in the water is everything below the anti-ventilation plate. That's why I've been concentrating on that area, and the hull.

Re: Hull Blueprinting
 

Handling was fine to start with. As I stated in an early post, it appears my bottom was very good to start with. Probably a good comment on the quality of Hustler's mold work. Shop that did mine also has done quite a few as well. I suspect how big the net gain will be is a result of how bad the bottom is to start with.

Re: Hull Blueprinting
 

I own a 89' Formula 272SR-1. Have you ever worked on this model?

I called Formula and they said that the "hook" is actually a "wedge" they insert in the mold as additional material. The hook starts about 24 inches from the transom and is about 1/2 inch thick. I would thick that removing some of the hook would unlease this boat! It runs 72-73 mph and hits a "wall" I have twin 525hp motors but know someone who has twin 645hp motors in the same model and he can't seem to break 80mph.

1989 292's and 311's don't have hooks but seem to be faster boats with the same power. Whats your opinion?

Dan

Re: Hull Blueprinting
 

I have a hook in my hull also. I have been working on cleaning off the bottom paint and found this hook on the pad area about a foot off the transom. It may be a 1/8" . Right now my boat runs very wet. I have been thinking that this hook is keeping me from loosing up the grip the water has on me. You can see the hook right buy the FaxMax wording. the hull is a 251 GTX checkmate
http://i65.photobucket.com/albums/h2...4/100_0295.jpg

Re: Hull Blueprinting
 

Don`t forget that many hull`s has a slight hook built in by the manufacturer. This is for help with planing and for reducing porpoising.

Re: Hull Blueprinting
 

Anyone modified a late 80's Formula 272 SR-1 hull/hook?

I really need some input.

Re: Hull Blueprinting
 

Mtgbiker,

I have the same hull running 93+ on GPS and haven't done any work to the hull YET. I don't think the wedge is an issue for top speed because it is between the outside strake and chine only. I think we will see more gain from extending the inside strake and or adding a pad.

Re: Hull Blueprinting
 

Cay,
Why do you think the 292 and 311's don't have a hook. The 272 should be faster than a 292 with the same power right?

It seems that the lighter 272 would be faster than the 292 but aren't. The 292's don't have hooks. At least the 88 thru 90's that are on my lake don't.

What do you think?
mtgbiker.

Re: Hull Blueprinting
 

Does blueprinting a bottom help on a boat that is bottom painted? Seems like you are making it perfect, then coating over it.??

Re: Hull Blueprinting
 

mtg,

Not sure why the 292 would be faster but it could be something simple like the x-deminsion or the strakes might be different. I installed IMCO 2" shorties and picked up 4mph even going from a 3 blade prop to a 4 blade so if the 292 has a higher x it could easily be as fast or faster.

If I don't decide to sell my 272 I plan to try extending my inside strakes and possibly installing a pad in an effort to take it over the 100 mark.

Re: Hull Blueprinting
 

What is the difference between a strake and a chine and the pad you are talking about, is that the same as the notch in the back of tha fountains?

Re: Hull Blueprinting
 

On a V-hull a strake or lifting strake is usually about 3" wide starts at the bow and goes to the stearn of the boat. On many hulls the strake closest to the center stops a few feet short of the Stern while the one furthest away from the center usually runs all the way. The chine can be thought of as a strake placed at the outside edge of the bottom. In the case of the Formula 272SR1 they have a wedge (similar to a built-in trim tab) between the outside strake and the chine. Hope this answers your question.

Re: Hull Blueprinting
 

Mike Paula,
Becareful removing the hook from the 251 Check.. I did it and it caused some serious handling problems.. Give me a PM and I will explain. I have posted this info before, so a search may bring it back up..

Dick

Re: Hull Blueprinting
 

Dick
sent ya a pm.
Mike

Re: Hull Blueprinting
 

What is the step by step procedure, area of interest and how long a straight edge to check for hull hook on a 25ft Nordic Rage?

Re: Hull Blueprinting
 

Anyone?

Re: Hull Blueprinting
 

Does anyone know of a good shop in the central Florida area that would do the bottom on a 302 Baja?

Thanks
Dail

Re: Hull Blueprinting
 

Who would be closest to StLouis that knows what they are doing to blue print a Nordic Rage hull?

Re: Hull Blueprinting
 

OK

Re: Hull Blueprinting
 

Anyone?

Re: Hull Blueprinting
 

Obviously I am looking for the closest that does the good work. I would travel as far as required to get the good work.

I just checked my 25 foot Nodic Rage hull with a five foot rule (too long). It appears that I have a gradual hook of about an 1/8 inch max from the step hull to about one foot from the stern edge where the hull reverses and falls away to about a 1/16 inch at the stern edge. What is the prognosis?

Re: Hull Blueprinting
 

How much mph drag would these hull dimensional imperfections create for high 70's.

Re: Hull Blueprinting
 

Still looking for an answer.

Re: Hull Blueprinting
 

Using the SWAG theory (Simple Wild Ass Guess) I would estimate 2 mph to 4 mph. My father has blue-printed the bottoms of his Magum, Pantera, Cigarette, Donzi (the Phantom bottom did not need and sanding). The Donzi was a mid-60 mph boat and gained 2 mph, I do not remember the how much speed, if any, was gained on the other boats.