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School me on tunnel hulls...
Posted: July 4th, 2013, 3:10 pm
by Badbagger
As the topic says "school me on tunnel hulls".. having just completed a one total rebuild, seriously thinking of looking around for an all welded tunnel to play around with in the 16' to 17' range. I've read that they won't float as shallow as a non-tunnel due to less water displacement, they're harder or close to impossible to be able to use reverse on your engine due to the tunnel, require more HP than a non-tunnel, pretty much have to invest in a jack plate & they will not handle like a conventional boat.
Any input appreciated..
Re: School me on tunnel hulls...
Posted: July 4th, 2013, 4:01 pm
by Jumptrout51
Displacement is a non-issue if it is equipped with sponsons.
They are made for running shallow,not in reverse.
Re: School me on tunnel hulls...
Posted: July 4th, 2013, 4:04 pm
by Badbagger
Thanks JT. Only issue I can think of with sponsons would be transducer placement limitations.
Re: School me on tunnel hulls...
Posted: July 4th, 2013, 4:10 pm
by Redbelly
I had a 16' Scandy White. Awesome for running wide open in 6" of water. The one time I did it was the only time I wanted to do it.
I think you must have a HJ to properly use a tunnel. Backing up is a slow response thing. With a HJ you can lower the foot deep enough to get a somewhat useful reverse.
The transducer was mounted on the rear of the sponsoon.
Other than the tuffness of the Scandy, the flat bottom G3 I have now fishes in the same water I fished with in the Scandy. I do go a lot slower.
For an aluminum tunnel i don't think you can beat a Scandy.
Re: School me on tunnel hulls...
Posted: July 4th, 2013, 4:13 pm
by Badbagger
Thanks, I use to work in Blountstown and have been at their shop and they make a great boat no matter what it is.
Re: School me on tunnel hulls...
Posted: July 4th, 2013, 4:51 pm
by charlie tuna
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The lost displacement is very small, because the actual tunnel is small. The idea is the pressure created by the hull forces water into the tunnel and creates a column of water for the prop to operate in. There is a lot of water flowing up and out of the tunnel during normal operation. Get into some skinny water and the hull raises up, and the prop continues to push the hull -- it is kind of strange to experience!!! I don't like this kind of experience!!! If you know the bottom, i guess it's fine. I have run in six inches of water in the keys -- not on purpose either. This is an 18 foot hull that carries a lot of weight.
PS: you can see the transducer to the right, not a problem.
Re: School me on tunnel hulls...
Posted: July 4th, 2013, 5:15 pm
by Badbagger
Thanks Charlie and getting into skinny water that you don't know would be unnerving. I'd imagine to an extent it can also provide a false sense of security. Maybe in Texas where the worst would be running into sand would be not so bad, but around here it's the rocks that'll be you in the azz and that's a bad bad day.
Re: School me on tunnel hulls...
Posted: July 4th, 2013, 8:31 pm
by charlie tuna
I used this boat in Everglades National Park for years --- no need to worry about the bottom there!! Never had a problem. Then started using it in the lower keys, near the Content Keys. No problem. Now up in the panhandle is a different question!! Put a hydraulic jack plate on it, but still a little intimidated about using it here?? But am considering it.
Re: School me on tunnel hulls...
Posted: July 5th, 2013, 6:36 am
by tin can
Charlie Tuna gave a very good explanation of how a tunnel works and what it's for. It's designed to run in near no water. It usually gets very expensive for those that run in real shallow water in this part of the world.

I would suggest a good flat bottomed boat, a hydraulic jack plate, a water pressure gauge, and a good prop designed to run vented. Then take the time to experiment and get the boat set up properly. The Gatortrax I used to have was set up this way. The boat would float in 6" of water. It would get up in 12" of water. Showboat will confirm that, once under way, it would go over an oyster bar that was nearly exposed.

However, the trolling motor would bottom out well before the boat would.
For me, it was much more important to fish skinny than it was to run skinny
Re: School me on tunnel hulls...
Posted: July 5th, 2013, 8:42 am
by SHOWBOAT
tin can wrote:Charlie Tuna gave a very good explanation of how a tunnel works and what it's for. It's designed to run in near no water. It usually gets very expensive for those that run in real shallow water in this part of the world.

I would suggest a good flat bottomed boat, a hydraulic jack plate, a water pressure gauge, and a good prop designed to run vented. Then take the time to experiment and get the boat set up properly. The Gatortrax I used to have was set up this way. The boat would float in 6" of water. It would get up in 12" of water. Showboat will confirm that, once under way, it would go over an oyster bar that was nearly exposed.

However, the trolling motor would bottom out well before the boat would.
For me, it was much more important to fish skinny than it was to run skinny
Confirmed! TC knows how to set up boats and his GT was impressive. As we headed on a back route that required going through cuts barelely deep enough to cover ones ankles and spartina grass under both sides of the boat I often found myself looking back to see how we were still running. Expensive to inexpensive, he can get the most out of a boat. Looking at the hull alone is not enough. A jack plate and the right prop can be very important as can the weight distribution and water intake.
Re: School me on tunnel hulls...
Posted: July 5th, 2013, 9:06 am
by charlie tuna
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This is my jack plate set up. I have never noticed any difference backing down in a tunnel hull? Up here, speed is the last thing to think about..
Re: School me on tunnel hulls...
Posted: July 5th, 2013, 9:16 am
by guthooked
I have a 21 ft Kenner tunnel and can say that I don't have any big problems in reverse. They are not quite as responsive in reverse than a non tunnel but no big issue. If you make a hard turn at high speeds it will wash out a little but this is not really a problem either. I have a lot of problems with my transducer holding bottom and I think it might be related to he turbulence but I am not positive. I have ruled out everything else.
Just my two cents worth
Re: School me on tunnel hulls...
Posted: July 5th, 2013, 11:51 am
by Badbagger
Lots of great input and thanks. I've got a flat bottom all welded boat with a 72" bottom with a hydraulic jackplate and water pressure gauge. Everything BUT the tunnel.
Re: School me on tunnel hulls...
Posted: July 5th, 2013, 11:57 am
by Harmsway
Badbagger wrote:Lots of great input and thanks. I've got a flat bottom all welded boat with a 72" bottom with a hydraulic jackplate and water pressure gauge. Everything BUT the tunnel.
How much you asking for her, Badbagger? :?:
Fishin' is the mission.
Re: School me on tunnel hulls...
Posted: July 5th, 2013, 11:59 am
by Badbagger
Not for sale

Just adding to the collection.