small slow tunnel boat

[charlie]

I am going to build a 12 or 14 foot long
4 foot wide flat bottom john boat.
construction will be 1/4 inch plywood
bottom. add one inch thick by 16 inches
high sides...
I want to build it as a tunnel boat because of all the shallow water and sand bars in my location....
I am not concerned with speed or getting
up on plane...
can someone help me with the size of the tunnel I need to build?? I am going to
use a small five hp motor.
Any ideas or plans would help me alot

thanks Charlie

[Baz]

If your looking for shallow draft a tunnel hull is no way to go. For minimal draft w/ 4 ft Beam 14 ft LOA I would go with a flat bottom skiff. 5hp? I would go with a relatively flat rocker. You'll get a boat with plent of room inside. I have a wooden 14ft and can carry 4 adults. 1/4" bottom, FRP or Wood? FRP thickness is OK but 1/4" wood is too thin. Good luck.

In the Newport area, many work boats, and even new fiberglass flat bottoms, have tunnels in them. Most are larger ones in the 16 to 18 foot range. It is a lot of work, to build it in a plywood hull, for what you will gain in it. There is a hull sold at some of the marinas, in Havelock, that is really cheap, around 1200 dollars, that will fit your need. They were the old Allandale hulls, but has been copied by some other makers. It is blunt on both ends, and straight sided, and will work for that size motor. The little draft, that a 14 foot hull will have, you can work it, with trimming that size motor up. on that boat. You will only gain two inches with a tunnel, in that boat. You can build the boat with 1/4 inch plywood, but your will need to reinforce it with frames and runners on the bottom. I would not suggest it for the Newport River, though.

[charlie]

orster thank you for your reply...
I plan on building a flat bottom boat with flat bottom plotons... 15 inches wide... by 15 inches high.
tunnel is 24 inches wide 10 inches high...the draft of water in the tunnel should be enough to raise the motor by 4 inches..
what do you think??? this is not a N.C. type tunnel boat... It is a florida flats boat design..
see www.flatscat.com for more info.

I would love to get info about the old n.c. tunnel drive inboard motor.... like the small inshore shrimp trawlers used in Bogue sound and the core sound... thanks in advance for any info you can give me


Charlie

This is a little bigger than you may want at 19', but you may find something useful.

http://www.dngoodchild.com/7854.htm

I watched the cat style boat, go together, that you referred to, here, on another forum. As far as the tunnel style boats. go down to Harkers Island and Marshalburg, and root around. There are plenty laying around in yards, that can be had for the the taking, if you dare. Go over to Bock Marine, and check on abandoned hulls. Most are built from Juniper, white cedar, as it is known in many other states.

It appears I got logged out. I don't know if any plans are out for that type tunnel boats, in that size.

[charlie]

oyster thanks again
I will go down east and look around..I am not looking for a fast boat..just something to putter around in shallow water...I try to avoid the ICW and all the snow birds going back and forth to flordia and N.Y. city..
Thanks

Charlie

One thing of note, Fort Macon Marine, in Morehead City, across from Capt. Jim's Seafood market, had some small 14 foot catamarans, really dirt cheap. They were having a time selling them. The last time I was around the Atlantic Beach branch, they had one that was three years old. There is little room on deck but went in shalllow water. Looks sells. Check out this link for soem small shallow draft stitch and glue boats. I did a phantom 16 and have a Nina 22 to do this winter..

http://www.boatplans-online.com/index.php

[charlie]

thanks
I will go see what they have...
My e-mail address is
barbarw@webtv.net
lets keep in contact..

Charlie

[Baz]

How about building a jet drive skiff? low draft, unexposed impeller, take a jet from an old jet ski and adapt it to a flatbottom skiff?

[Jimboat]

Kits or plans to make a performance tunnel boat or raceboat are very hard to come by. The primary reason is that the costs of perfecting a tunnel boat design are very high for most commercial designers, so once they have a design that works well, they don't usually let it go!

The "Tunnel Boat Design Program" software would definitely help you with your design of your tunnel boat. As you have no doubt found, there are no plans available for tunnel boats around. We don't sell plans for boats, but the software helps you complete your own design that will work! Drawing the plans is the easy part. There aren't too many plans for tunnel boats around, and those that are, are several years old. Check out Glen-L Plans and Clark Boat Plans. They will have plans that show the construction details. There are several old powerboat designs at Svensons Plans. But I suggest you modify their designs, as some of the concepts are as much 40 years old!

You could also check out the Secrets of Tunnel Boat Design book.

[charlie]

thanks for your reply
You are sure correct there are very few plans for a tunnel boat...I am going on with my on plans, in fact I have already started the boat..I made one befor by accident that did not work which gave me the idea for this one..
I was making a small pontoon boat for a lake close by... I made the pontoons way to small in height and in width...but I noticed that the hull was sinking low enough in the water that I could put the motor in the tunnel and not drag the bottom...My idea of a tunnel boat that I want to use is different from most people in that I do not care about speed or getting on plane...I had a boston whaler jet drive boat...fun for a while but not what I wanted...

My boat 12' lOL...4'6" beam
Hull 20" high on each side.
two flat bottom pontoons each 16 inches
wide and 12 inches high
width between each pontoon 24"

Hard to explain but that should give me
at least 5" to raise the motor into the tunnel....

motor will be a 5 hp or a 10 hp outboard
or even a small inboard....

I am going to build the boat in stages so I can test it and not spend a lot of money on fiberglass and epoxy...