Tunnel hull?

[PSG-1]

As many of you know, I have an inboard jetboat. As good as it performs in shallow coastal waters, I will not take it to inland rivers where there are rocks. Mainly because the boat weighs 1200 pounds, and all it takes is one miscalculation to be hard aground. Also, even with my modified intake grate that works like a stomp grate except it uses a push-pull cable….i know that it only takes one little stone to lock up an impeller.

As such, when I go to areas like that, I use my 14 foot johnboat with a 25 outboard.

Even with a transom jack and float pods, I still have concerns about the lower unit.

What about a tunnel hull modification? Anyone have experience with these? If so, I’d appreciate any advice.

 

[Axhammer]

A tunnel hull added to your current boat and the same outboard will get you more shallow water capability.

If you want the ultimate shallow capabilities, put a jet outboard on a tunnel hull Jon boat.

A properly rigged Jet outboard on a tunnel hull Jon boat will run in very shallow water.

 

[Hooligans]

This Alweld 1448 was built with a raised transom and a tunnel. It works well. It goes as shallow as anything if I stay on-step. The good news is when I get stuck or get a rock in it I can easily get out and handle it manually.

 

[Hooligans]

To be more clear, I have had a rock in the impeller and needed to drag it onto a ssndbar to deal with it. And what I've learned is that although I can run in just a couple inches of water at speed, I can't stop without getting stuck, but it's so light that it's easy to get un-stuck by hand, pushing it into deeper water. Needs about a foot of water under the foot to go again without pumping gravel.

 

[FuzzyGrub]

When I read your post, assumed you were talking about a prop tunnel, which are generally deeper/taller and longer than a jet tunnel. Never touched or even seen one in person.

If you are talking about an outboard jet tunnel, you will find dimensional suggestions on the Outboardjet.com website.

 

[Hooligans]

What about a tunnel hull modification? Anyone have experience with these? If so, I’d appreciate any advice.

Sorry... I thought you were asking about if it works well. I have no experience doing the mod.

 

[oilsmoke]

My main experience with a tunnel hull boat was on a larger, inboard powered boat.
While it likely often protected the prop and let me get into some pretty shallow water, around the dock it was miserable Tunnel hull boats do fine in forward but reverse can be a real issue. Mine did everything well but back up. Since I had to back into my slip, it was a nightmare to try and fight the current and get the boat to move in reverse under any sort of directional control. In reverse the prop thrust was directed more downward than forward. For a boat too heavy to manually move around, that was a real issue.