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Wide Pontoon Houseboats - will they provide stability, or are more stable?

by Dave
(Redding, CA.)

Wide Houseboat Pontoons - are they stable, or have stability?

Wide Houseboat Pontoons - are they stable, or have stability?

I have a 31' x 8.5' trailerable houseboat, (pictured above) and I have decided to widen it out to 12 feet. My local welder has decided to add an additional 18" onto the existing pontoons with additional compartments, and then pressure test the job after it's complete.

He feels this is the best way to go, being that he would have to cut all the cross members in order to remove the pontoons. Is this the best way to go, and will this make my houseboat more stable, as far as rocking back and forth?

Any help would be appreciated, Thanks, Dave.

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Reply - Answer
Well Dave, welcome to the houseboat forums, and sorry to hear about your problem with the back and forth rocking.

You are not alone when it comes to lateral stability on narrower houseboats. The wider houseboats suffer less from the back and forth sideways motion, especially when you look at 12, 14, 16 foot wide models.

I would venture to say that in theory it will provide more lateral stability, however at the expense of reducing the trailerable houseboat aspect.

You maybe interested in looking at the Travelwave 360 houseboats, as they have an interesting design concept of making the exterior pontoons pivot up to the roof when traveling.

From a mechanical and engineering point of view for floatation and stability, maybe someone in the houseboat community can post their views and opinions on widening your boat.

Lastly, hopefully some of our readers will share and post comments about their pontoon width, and their houseboat stability experiences. Feel free to use the "Click here to post comments." link found near the bottom of this page.

Thanks again for sharing, IAN from all-about-houseboats

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Comments for Wide Pontoon Houseboats - will they provide stability, or are more stable?

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How tall can it be?
by: Chuck

Dear boat guys, I have a 1973 Chris Craft Aquahome. The cabin is almost completely rotted and I plan to rebuild on the hull. The boat is 46' long and 12' at the water line. Is there a formula for width vs height on this type of hull?

I would like to add a second 7' floor over the back portion of the original boats design. That would make the back half of the boat about 5' taller than the front portion where the steering wheel and the kitchen is.

Is this a crazy idea?


P.S. Incase you have not figured it out this is my first boat of any kind.

Sealed chambers and foam
by: Anonymous

If you have a foam roofing contractor in your area, make friends. The foam used is 2.5 to 3.00 lb density closed cell foam. I was in the business years ago. When finished with a roof there were always bags of trimmings. They went to land fill until I got a hot thought.

Raw foam is expensive, but the chunks and cuttings are free. If you spray a bit of raw roofing foam into the pontoon chamber, then drop in the cured free chunks, then spray a bit more and add more chunks, you wind up using very little raw foam.

Be sure to go chamber to chamber filling a few inches at a time to give the raw foam time to off-gas. Be patient, but it will be done in less than half a day and you can hit rock, tear gashes, shoot hole in your hull all day and it will never sink. Not a chance. I don't know why more people don't do it. Seems a shame to let all that unsinkable foam go to waste in some landfill.

Also, the same company may be able to spray "primary and secondary contact" poly-urea. Check the stuff out. It's so tough it can be a boat hull by itself (although very expensive in that case). As a hull coating it is perfect and will take a lifetime to wear away (higher abrasion resistance than some steel).

It can be used for potable water tanks and primary food contact but it can also be used for secondary emergency containment of gasoline, oil, and many acids-- nothing in the water like that we hope) and grasses and critters can't bond to it easily, so it wipes off easily. Check it out.

Get the Bigger Boat you Want!
by: Russell

Don't get into the cost and design problems with widening a boat. Sell it and get what you want. It is a buyer's market right now. If your old one is paid for you can park it until you get a good offer.

Getting another wider boat is very affordable right now. I know of several houseboat bargains right here in the N. Fort Myers area. I know of a 50 footer with a couple of nice running outboards for $15,000 and another 38 footer for $7,500.

I am sure there are a lot more out there. I even know of some who will finance them for you with a small down payment. So, don't mess with a major re-design problem. Sell it and get what you need.

Modify the pontoons on a houseboat
by: Old Houseboater

What you propose is doable, however it will cost you a lot of money and destroy the value of the boat. Strongly suggest you sell the present boat and purchase a Catamaran Cruiser or Aqua Chalet or ???? in the width and length that meets your requirements. You will be further ahead, in regards to the money and hassle.

Width and Stability of Pontoon Houseboats
by: Bill V. Fla.

You are correct in thinking of widening to make more stable. Adding to the length will help to make up for the extra weight.

Be sure not to add too much weight, (W x L=D) weight x length = diameter. When a houseboat is designed, especialy trailerables, the weight to diameter ratio is worked out.

Try to stay within the parameters of the formula.

Adding 3rd toon
by: Bill Monteith

Have you thought of adding a 3 toon to the center of it? I just sold one that I did, it was the second toon we have added them to.

It helped with rocking of the boat in both directions. I have found a lot of single toons when I went looking for them. So finding them isn't a problem and it doesn't take a lot to add them.

Makes them ride a lot smoother, and setting up in the water helps out everything. Able to haul more folks and equipment is nice. Makes building on to a lot easier too.

I had one toon cut at the back to mount the motor right on the toon. It was about 4ft longer than other two, so doing this made 2 foot out the front, with the center toon out longer than the other two really made it turn and ride great.

Good luck. a lot of ideas out there, take your time and do it right.

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