Bottom of my boat

[n8dawg]

I want to get the pump rebuilt and a place diverter bolted on but first I read that I should check the bottom for hook. How do I do that? Can i run a straight edge under it or do I have to flip the hull over?
Thanks.
Nate

[MudPumper]

get a long straight edge and crawl under it. You'll be able to see if it has hook or rocker.

[BrendellaJet]

You are really only concerned with the wetted surface. Measuring between the last strake and the chines you are probably gonna see some hook or rocker, but at speed on most 18 footers this area is out of the water.

[Squirtcha?]

Whether it's on the trailer or off, when you make your checks, one end of the straight edge should always be past the transom by an inch or so. The transom is your reference point.
http://www.jetheaven.us/photopost/data/500/19straight_edge.jpg
Although it's possible to check your boat while it's on the trailer, I've found that it's not very accurate. I knew mine was messed up, but had no idea how messed up until I got it flipped. The quick check on the trailer will give you an idea of how bad it is, and whether you should pursue the blueprint though.

[Cole1313]

get a long straight edge and crawl under it. You'll be able to see if it has hook or rocker.
Yep!

[El Prosecutor]

Whether it's on the trailer or off, when you make your checks, one end of the straight edge should always be past the transom by an inch or so. The transom is your reference point.
http://www.jetheaven.us/photopost/data/500/19straight_edge.jpg
Although it's possible to check your boat while it's on the trailer, I've found that it's not very accurate. I knew mine was messed up, but had no idea how messed up until I got it flipped. The quick check on the trailer will give you an idea of how bad it is, and whether you should pursue the blueprint though.
I wonder, especially on older boats, if gravity and the weight of the bottom would effect the measurements when the boat is flipped? In other words, isn't it possible that it would actually sag a little?

[Squirtcha?]

I wonder, especially on older boats, if gravity and the weight of the bottom would effect the measurements when the boat is flipped? In other words, isn't it possible that it would actually sag a little?
Absolutely.
Consider too that you've taken 800+ lbs of motor, the seats, etc. out of the boat, then you're flipping it upside down. You know that's gonna change some things around.
I received some instruction from a guy who is probably best in the business (hull blueprinting). He strips em, flips em, then makes em straight. So all the other considerations aside I guess that's the best you can do with em.
The area that you see in the photo (gray area) is way to thick to sag. I blueprinted that last year. The fiberglass is at least a 1/2" - 1" thick in that area.
Now outboard of that area (the place that I need to work on now) is very thin and you can push on it with your thumb and see it bow/sag. Typically this area is not included in the blueprint. I'm building it up due to the bottom getting damaged in that area. The main reason for building it up, is because it's very thin and weak to begin with and probably why it delaminated. Had it not come apart on me, I wouldn't even be messing with it.

[n8dawg]

Thanks for the info guys. Always a lot of help to me. :)