need to add width to bottom surface of aluminum boat

[firstinfireman]

I have a 20'x 36" aluminum tunnel hull boat for fishing shallows and running marshes in south louisiana during low water periods of our duck season. i am looking for ideas to add some surface area to the bottom(width) i was thinking of having some 3"x3" aluminum angle welded to make it a 20'x42" boat but wondered how you guys thought it might affect performance. What i am looking for is a little more planing surface to get the stern up out of the water a bit more on plane as well as decrease planing time. I cant use trim tabs due to mu low water conditions.

 

[firstinfireman]

adding bottom width... suggestions?

adding bottom width... suggestions?

I have a 20'x 36" aluminum tunnel hull boat for fishing shallows and running marshes in south louisiana during low water periods of our duck season. i am looking for ideas to add some surface area to the bottom(width) i was thinking of having some 3"x3" aluminum angle welded to make it a 20'x42" boat but wondered how you guys thought it might affect performance. What i am looking for is a little more planing surface to get the stern up out of the water a bit more on plane as well as decrease planing time. I cant use trim tabs due to mu low water conditions.

 

[jhow0228]

Re: need to add width to bottom surface of aluminum boat

Have you thought about adding sponsons? Would probably be an easier fix than expanding the entire length. I'm not sure how much more lift you'll get on plane, but I know it will decrease planing time and depth.

 

[jestor68]

Re: need to add width to bottom surface of aluminum boat

This will lift the stern and get you on plane more quiickly. It's called the Doel Fin.

 

[Bob_VT]

Re: need to add width to bottom surface of aluminum boat

There are people I have seen who have added sponson type boxes to the stern of the boat to add surface area to the stern. Are you running a jet motor? How about a jack plate? That is a very narrow and long boat and it could also be a question of balance. What type of steering are you using? Tiller? Console? Post a few photos of your boat/motor combo.

Now is this a homemade boat or stock? There are many parts to this equation so, before you throw any money at it.......let's do some more looking Boat, motor (type and HP) set up etc.

 

[jigngrub]

Re: need to add width to bottom surface of aluminum boat

Buy a wider boat, your boat is what it is as far as length and width.

I've seen the sponsons installed on boats, and people claim they do a good job... but your transom wasn't designed for that additional weight or the leveraged downforce they create out of the water. I suspect sponsons would shorten the life of your transom and cause structural problems down the road.

 

[robert graham]

Re: adding bottom width... suggestions?

Re: adding bottom width... suggestions?

You could have some aluminum floatation pods welded on the back to help float the stearn up more...

 

[Georgesalmon]

Re: adding bottom width... suggestions?

Re: adding bottom width... suggestions?

I have an 18' jon with pods as described by Robert. Have a 50hp four stroke yamaha on it. Before I put the pods on it was slow to plane and rode low in the stern. With the pods it gets up quick and will run slower and stay on plane. They are on either side of the motor about 14" long and 18" wide. Level with the hull planing surface. They are filled with flotation foam. My boat rides higher and more level at rest to. Not a tunnel hull though. We use it for duck and goose hunting in WI. I have angle around the tops and also adds more area for storage such as a waterproof shell bags bungeed on.

 

[JB]

Re: adding bottom width... suggestions?

Re: adding bottom width... suggestions?

I have merged your two threads. Please respect our rules.

11. Please do not post multiple threads in multiple forums about a single problem. This is confusing to those trying to help you. Multiple threads in the same forum about the same issue are also confusing. If you want help fast, one thread in the most closely related forum is the best way to get it.

 

[firstinfireman]

Re: adding bottom width... suggestions?

Re: adding bottom width... suggestions?

I have merged your two threads. Please respect our rules.

11. Please do not post multiple threads in multiple forums about a single problem. This is confusing to those trying to help you. Multiple threads in the same forum about the same issue are also confusing. If you want help fast, one thread in the most closely related forum is the best way to get it.

I do apoligize for mis using the forum, i had not read the rules.
thanks for the help guys keep em coming , the dolphin tail will not help due to my tunnel the cav plate already rides above ewater line. can you add a picture of your boat with the "angle for more storage" thank you guys

 

[firstinfireman]

Re: adding bottom width... suggestions?

Re: adding bottom width... suggestions?

ok i finally got some pics, i am currently running 5.5" setback and 6.5" above transom i ordered a cmc tilt plate that should give me the same setback and lift plus tilt and trim. I could add float boxes but dont know how well they would work as the sides of the tunnel are only 12" wide. I also thought about adding tunnel extension to get more water pressure at the prop. thoughts?running a powertech nreb 13p with heavy cup
5100 rpm at 34 mph empty
4800 rpm loaded @29 mph

 

[64osby]

Re: adding bottom width... suggestions?

Re: adding bottom width... suggestions?

I would look at your options to modify this boat and put a cost to it, time and money.

At the same time look for a wider flats boat that would suit your needs.

IMO - the time and money will wash or be higher than picking up a wider hull.