how do tunnel (drive) hulls work?

Yes, several inches of the tunnel are above the water surface.

If you really wanna see something cool, check out the videos and stuff at www.flatscat.com - that boat will run with the entire propeller above the surface of the water.

 

I'm new here, so if I violate etiquette - my apologies in advance...I'd like to tag on to this older post with a new question.

Long story, short...I had a custom build Alumacraft VB1650AW w/prop tunnel ordered, blew up my lower on the river, and I'm reconsidering the entire venture.

The hull is called a "flat-V tunnel", I think it's something less than 6 degrees. It has a 27" transom (20" to top of tunnel for standard lenght outboard) and "step" pontoons.

My main purpose for the boat is river fishing in western Michigan, large rivers with plenty of areas of skinny water...

My questions:
- do I stick with the hull and get a new outboard (prop) or will I be better off with a jet tunnel?
- do I need sponsons with a jet tunnel to compensate for lost buoyancy?
- I'd also like to use the boat on larger rivers and lakes, is a jet a poor choice?

I've heard many opinions, but would like to hear from someone with experience running a "factory" prop tunnel.

Thanks in advance.

 

That Alumacraft looks like a decent hull. The only reason I would go with a jet is if you have a lot of shallow rocks that you can't typically see in the areas that you run. With a good prop setup, you won't hit anything that's a few inches below the boat hull - you can usually see ripples formed by rocks, stumps, etc. if you're running in a river, so you can avoid those.

With a tunnel, you'll want a SS prop - I recommend Baumann Props or PowerTech Props - give them a call and tell them what you have and they will work with you to get you the right prop. You will need a tachometer to get the right prop, and a water pressure gauge if you are using a jack plate.

If you go jet, you need a different tunnel (three inches high vs. six inches high for a prop). The pods mainly help you with holeshot in shallow water. If you don't typically need to get up on plane in shallow water, you could probably forego the pods. Their other advantage is offsetting the weight of the motor.

Again, the only real advantage of the jet is if you typically run in rock-strewn waters where you can't see the rocks (or ripples from them). They can get up a little shallower than a prop, and maybe run an inch skinnier, but in most cases aren't worth the hassles.