Adding a 3rd toon

[Ats666]

Hi, I've got a 1988 18 foot pontoon with 19" toons on it.
How big of a center toon can I add without stability issues

I'm not trying to go faster, just want more buoyancy out of it.
There is a guy selling new and used toon relativey close to me but they're all 23-25" in diameter.

Thanks

 

[HotTommy]

A few questions:

1. Will the center log have the engine pod or will it be a short center log?
2. How low in the water does your boat sit now (e.g., half way up the logs)?
3. How much will the center log weigh?

 

[Ats666]

1. The center toon will be about 10feet long. My plan is to have the rear of it stop at the engine pod.
This boat is only for fishing with a low hp motor pushing it.
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2. Yes it sits about half way up in the front and an inch or so lower in the rear.
Id like to reconfigure seats and gear once it sits higher
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​​3. Not sure on the weight as of yet. I'll have to cut to fit once I get the toon in hand. Depending on what's available I might be able to get a center toon with storage

 

[5150abf]

A center toon with storage would require a redeck and special crossmember section where the opening is so unless you have a pretty extensive fab shop probably not that one.

Adding a short "pony" tube should e pretty easy as long as your bracket spacings are the same, i.e. both 24'' or 16'' to match your boat.

If you get a 25' tube the front section should be @120'' long, you can just cut off the rear section and you are good, should have a sealed baffle between the sections

 

[HotTommy]

I've thought about this a bit and here are the most important facts. 1. I've never done what you want to do so I have no real world experience. 2. You want to add both weight and bouancy to the front, but not the back and that makes it difficult to predict what would happen. ... My GUESS is that the boat will sit more level at rest and ride slightly higher in the water (an inch or so). At speed I would be surprised if it felt much different although it could tilt a little in hard turns. As the bottom of a 23" log will be only about 2" lower than the bottom of a 19" log, I wouldn't expect much difference. .... If your plan is to use the added log to carry more load, add it in the front.

 

[Groo]

If you want boyancy to reduce draft, a large diameter shorty center toon won't do it since it will become the new low point. You will also reduce stability since you will have the teeter tottering thing going on.

how about pick up a cheap toon with trashed seating and no functional motor, and put larger toons under your deck. I see boats that would give you more flotation all the time for under $1000.