Adding a Third Toon, Ideal length?

[captmello]

I've been considering adding a third tube to my pontoon. It is listed in my sig.

I am planning to add a shorter tube in front of my motor pod.

I've found a 25" diameter tube that I plan to shorten with the help of a fellow Iboater who is willing to shorten the length of the tube for what I think is a more than generous price.

I'm trying to come up with the best "theoretical" length to make the tube, since I can make it any length I want.

My motor pod sits about 4 1/2 feet from the rear of the boat, leaving about 19 1/2 feet from the front of the boat to the nose of the pod. I've read I should keep the rear of the toon forward of the pod by about a foot +/-. I have 24"o.c. cross members so 18' would be about the minimum I think I would go in order to catch the 18' cross member, but could leave some extra beyond that if it seemed like a good idea.

So basically I've got a range of about 18-19.5' of space to use.

My boat has 23" tubes, so the center tube will be slightly larger then the outer tubes.

Any input is appreciated. but don't try to talk me into a full length tube with the motor mount, etc. I 'm fully aware of what I'm getting into.

 

[crb478]

Re: Adding a Third Toon, Ideal length?

Just guessing and thinking out loud here, but how well does your pontoon hook up in the water now? Does it cavitate in turns now or does it power through? Would your motor benefit by being a little deeper in the water or would remaining at the same height be optimal. If putting the motor deeper would help I would probably cut the toon to about 16-17 feet, other wise I would go about 17.5 to 18 foot. I would look at several manufacturers on line that add 3rd toons and guestimate the distance that they leave between the toon and motor pods. I would check out Avalon/Tahoe and Bennington and the hope for the best.

 

[captmello]

Re: Adding a Third Toon, Ideal length?

Thanks for the thoughts. Currently, I would say the motor hooks up pretty good. I can make it cavitate with some aggresive back and forth steering but for the most part, I haven't had any issues that bother me or worry me. I see your point however. Adding the third toon may raise the height of the motor. My motor is currently mounted at its lowest position.

 

[crb478]

Re: Adding a Third Toon, Ideal length?

on the Avalon site there is a picture of a added 3rd toon about 16 inches in front of the motor pod, (based on the under skinning rivets). That should help push the stern down a bit more than the bow. If needed you could add a jack plate to the motor pod to lower the motor, or try moving the third toon in front of the other two slightly. I think that the safest bet would be to cut it to about 18 foot or 18'2" and no shorter than 17'6" based on other factory set ups I have seen. That would give you a little adjustability and since it is basically a one time shot it's easier to cut more off than add more on so I would try 18 or 18'2".

 

[captmello]

Re: Adding a Third Toon, Ideal length?

on the Avalon site there is a picture of a added 3rd toon about 16 inches in front of the motor pod, (based on the under skinning rivets). That should help push the stern down a bit more than the bow. If needed you could add a jack plate to the motor pod to lower the motor, or try moving the third toon in front of the other two slightly. I think that the safest bet would be to cut it to about 18 foot or 18'2" and no shorter than 17'6" based on other factory set ups I have seen. That would give you a little adjustability and since it is basically a one time shot it's easier to cut more off than add more on so I would try 18 or 18'2".

I agree. I have considered the possibility of a jack plate, so as a lost resort I'll go that direction. Typically, I'm a bigger, longer, the better type, but in this case I'm realizing that's not necessarily true. After measuring my boat the other day, I need to go about 18'3" to get past, and bolt up to the 18' cross member of the boat, so I'm thinking 18'3" right now...

I also have a 29 gallon fuel tank that sits in the far back corner of the pontoon, so that adds quite a bit of weight when full.

But, I'll continue to research. I was shopping trailers yesterday at a boat dealership and they had boats with the express package. But they also all have lifting strakes and much more engineered toon shapes than my round tubes, so I didn't really see how I can compare the two. If they are still doing this on new toons, it can't be that dumb an idea.

 

[Cycleman07]

Re: Adding a Third Toon, Ideal length?

I agree. I have considered the possibility of a jack plate, so as a lost resort I'll go that direction. Typically, I'm a bigger, longer, the better type, but in this case I'm realizing that's not necessarily true. After measuring my boat the other day, I need to go about 18'3" to get past, and bolt up to the 18' cross member of the boat, so I'm thinking 18'3" right now...

I also have a 29 gallon fuel tank that sits in the far back corner of the pontoon, so that adds quite a bit of weight when full.

But, I'll continue to research. I was shopping trailers yesterday at a boat dealership and they had boats with the express package. But they also all have lifting strakes and much more engineered toon shapes than my round tubes, so I didn't really see how I can compare the two. If they are still doing this on new toons, it can't be that dumb an idea.

Check South Bay's Sport tube package online. You should be able to get some pics of the setup.

 

[captmello]

Re: Adding a Third Toon, Ideal length?

Check South Bay's Sport tube package online. You should be able to get some pics of the setup.

Thanks, but I'm not seeing any detailed pics or specs. Did you see some that I can't find?

Here are a few pics of my toon to show what i'm working with.

In this pick you can see the way the pod mounts. The 2" angle iron is mounted to the 18' cross member and the nose of the motor pod is approximately 18" further back.

Here you can see where the boat sits in the water. The port side has the fuel tank above so it sits a bit lower.

Here is a shot from the front. Not sure what good it is...

 

[Cycleman07]

Re: Adding a Third Toon, Ideal length?

The boat in the link below has one pic that shows sort of how it mounts up. It appears to nearly butt right up next to the transom pod. Most wont get into too much detail as far as specs go because of the competition etc.

Used 2013 South Bay Pontoons 522 E, Dewey, Az - 86327 - BoatTrader.com

 

[captmello]

Re: Adding a Third Toon, Ideal length?

The boat in the link below has one pic that shows sort of how it mounts up. It appears to nearly butt right up next to the transom pod. Most wont get into too much detail as far as specs go because of the competition etc.

Used 2013 South Bay Pontoons 522 E, Dewey, Az - 86327 - BoatTrader.com

Thanks, yes, that does look butted right to the pod.

I'm still thinking of going with the 18'3". The problem with all the express packages I'm finding, is that they are all setup for planing. I won't be planing the same with my old round tubes. So I just can't trust what they're doing with the center tube. Lifting strakes and 150hp. I'll have to wait 20 years for one of them to depreciate before owning it. What I do know is that it will have a much drier and smoother ride with the center toon. I'll worry about the performance when I can test it in the water.

 

[Bamaman1]

Re: Adding a Third Toon, Ideal length?

Go to a Bennington or Premier dealer to see if they have any 3/4 toons in stock. I have the Express Performance package on my new Bennie, and it does a great job. I got 90% of full tritoon performance for 1/2 the cost of a full tritoon.

FYI: A third toon without lifting strakes will subtract from speed, as they're heavier and produce additional drag. They've got to have lifting strakes to provide any real benefits, and they require 115 hp or more. All 3 toons do is handle slightly better, and carry another 1000 lbs. of people. Few people ever run with 12 or 13 full size people anyway.

 

[captmello]

Re: Adding a Third Toon, Ideal length?

Go to a Bennington or Premier dealer to see if they have any 3/4 toons in stock. I have the Express Performance package on my new Bennie, and it does a great job. I got 90% of full tritoon performance for 1/2 the cost of a full tritoon.

FYI: A third toon without lifting strakes will subtract from speed, as they're heavier and produce additional drag. They've got to have lifting strakes to provide any real benefits, and they require 115 hp or more. All 3 toons do is handle slightly better, and carry another 1000 lbs. of people. Few people ever run with 12 or 13 full size people anyway.

I've been toying with the idea of adding lifting strakes to the center toon. but I'm not sure if I will benefit from them with my 90hp. I am not opposed to repowering, up to the max 135hp, but that's not in the budget this year. The gentleman doing the welding on my third toon is more than capable of adding strakes and now would be the easiest time to do it...

As for the center toon slowing down the boat, I'm not sure. The tube only weights about 150lbs and must offer some lift. I plan to do a test run this spring to see just what my speed is prior to installing the third toon. And then a test after the third toon goes on.

Do You have any opinion on the length of the third tube? How far is your third tube in front of the motor pod?

 

[Bamaman1]

Re: Adding a Third Toon, Ideal length?

I'm glad you've got a welder that can weld aluminum and fabricate. They're really not easy to find.

Like I said earlier, go out and see how other dealers' 3/4 toons are mounted. I think it's 3' from the back of my middle toon to the start of the motor pod.

Lifting strakes don't appear to be very difficult to install, but the factories have done quite a bit of research on the shapes and angles of their strakes. Any fabricator would have to practice first, and then make the final welds. You don't want any pinholes or leaks. It's another thing to take measurements on lengths, angles, etc.

I have seen some 90 hp twin 25" toons with strakes. Don't be surprised if you need a larger motor on three hulls with strakes, however. It's just all trial and error.

And underskinning the rest of the underside is money well spent. I cannot get over how smooth my boat is in the big waves, and it's very quiet on topside due to the underskinning.


FYI: Bennington's fastest hull is their twin toon 32" elliptical (oval) toons with strakes. They have another 1000 lb. lift capacity vs. 25" toons. Ellipticals will be running 42 mph where my Performance tritoon with strakes will run 40 mph. The tritoons handle a little better than the ellipticals but much, much better than twin toon hulls, however.

 

[captmello]

Re: Adding a Third Toon, Ideal length?

I'm glad you've got a welder that can weld aluminum and fabricate. They're really not easy to find.

Like I said earlier, go out and see how other dealers' 3/4 toons are mounted. I think it's 3' from the back of my middle toon to the start of the motor pod.

Lifting strakes don't appear to be very difficult to install, but the factories have done quite a bit of research on the shapes and angles of their strakes. Any fabricator would have to practice first, and then make the final welds. You don't want any pinholes or leaks. It's another thing to take measurements on lengths, angles, etc.

I have seen some 90 hp twin 25" toons with strakes. Don't be surprised if you need a larger motor on three hulls with strakes, however. It's just all trial and error.

And underskinning the rest of the underside is money well spent. I cannot get over how smooth my boat is in the big waves, and it's very quiet on topside due to the underskinning.


FYI: Bennington's fastest hull is their twin toon 32" elliptical (oval) toons with strakes. They have another 1000 lb. lift capacity vs. 25" toons. Ellipticals will be running 42 mph where my Performance tritoon with strakes will run 40 mph. The tritoons handle a little better than the ellipticals but much, much better than twin toon hulls, however.

I would really like to get by with my 90 hp for another season or two. Its a great runner and has provided sufficient performance up til now. So I would like to come up with a setup that will work with the 90hp, without forcing me to repower because its a total dog on the water, or its cavitating as soon as I hit 10mph, or it handles weird, and so on.

One thing I should point out, is that the third toon I'm installing is 23" not 25" like the seller originally told me. so the center toon is the same diameter as the outers. I'm not sure if that changes anything or not. However, I'm thinking that since most center tubes are larger than the outers, I'm wondering if I will have less lift in the rear than a center tube that is bigger. Make any sense?

Because that is a concern, no? I don't want the rear end of the pontoon to high up in the water pulling the prop into the more turbulent water. that would be the reason for shortening the center toon, further back from the motor pod. In fact the more I think about it, I should wait on the strakes, and see what she does without. I can always cut it shorter, or add strakes later, or throw it in the recycling.

Underskinning is also on my todo list. that will will happen as soon as I'm comfortable with my center toon. thanks again for the thoughts.

 

[crb478]

Re: Adding a Third Toon, Ideal length?

I would really like to get by with my 90 hp for another season or two. Its a great runner and has provided sufficient performance up til now. So I would like to come up with a setup that will work with the 90hp, without forcing me to repower because its a total dog on the water, or its cavitating as soon as I hit 10mph, or it handles weird, and so on.

One thing I should point out, is that the third toon I'm installing is 23" not 25" like the seller originally told me. so the center toon is the same diameter as the outers. I'm not sure if that changes anything or not. However, I'm thinking that since most center tubes are larger than the outers, I'm wondering if I will have less lift in the rear than a center tube that is bigger. Make any sense?

Because that is a concern, no? I don't want the rear end of the pontoon to high up in the water pulling the prop into the more turbulent water. that would be the reason for shortening the center toon, further back from the motor pod. In fact the more I think about it, I should wait on the strakes, and see what she does without. I can always cut it shorter, or add strakes later, or throw it in the recycling.

Underskinning is also on my todo list. that will will happen as soon as I'm comfortable with my center toon. thanks again for the thoughts.

I went out today for the first time this year on my pontoon and then on a neighbors bennington tritoon, and noticed several differences in ride. My pontoon rides somewhat flat at a slight angle upward toward the bow. When I hit waves they hit the bottom of the boat and slow it down. His Tritoon rides with the bow much higher up and when it hits waves just skips over the tops. I don't know if shortening the center toon up by one cross member from 18'3" would help or hurt your boat. I know that on my pontoon when I add power the bow pushes down slightly and on my neighbors tritoon the bow raises higher into the air. With both boats side by side mine sets a little more bow high and his sets a little more level. I think that I would still stay with the 18'3" length , but that is just my guess. I think that I would also try the lifting strakes while you are at it. The lifting strakes on my center toon that I plan to add are just aluminum angle welded on and tied in at the front. Right now this is all trail and error, but hopefully you will get some positive improvements with this. Either way you can always return it to the way you started it needed.

 

[captmello]

Re: Adding a Third Toon, Ideal length?

Thanks for the response and first hand experience info. I'm kind of surprised there are not more people out there that have done what I'm doing, especially since tritoons have been around for a long time. But still, comparing the newer $50,000 bennington to my boat seems like a bit of a stretch. They are water tested by engineers and retested to achieve the ultimate performance. I can't so this, nor do i have the performance expectations of the buyers of those boats. Without the power to plane, I just can't base my plans according to what they are doing. My boat is going to have to push through the water, without planing. what will the strakes do to improve my performance? I don't know, and apparently no one else does either. I'm hesitant to add the strakes now because of cost and not knowing what they will offer. So for now I'm still on the fence with the strakes, still leaning toward waiting on them until i can test the boat without. If anything, I will be the guinea pig for all the pontooners out there who have considered this but have been afraid to pull the trigger. I have to admit, working on my boat and slowly making it better on a practical budget is half the fun for me.

Thanks again to all the Iboaters who have shared their opinions. I will be starting another thread soon to document the cutting down of the used tube I bought and the installation, along with before and after photos and performance data.
i hope you guys will watch and offer some advice/encouragement as I progress.

 

[crb478]

Re: Adding a Third Toon, Ideal length?

I totally understand waiting on the strakes. My understanding of them it that they provide lift by giving you a relatively flat area to allow the boat to plane, otherwise the water just flows up the round tunes without any restriction. I totally get you budgeting this and making a better boat in the process, as I am in the same situation. I can use/modify what I have or maybe rent something, but spending big bucks on a new boat is not going to happen. I look forward to seeing how your project turns out, and I am trying to be patient while I wait to borrow a friends trailer. Good luck with everything!

 

[luckyjr]

Re: Adding a Third Toon, Ideal length?

I've been considering adding a third tube to my pontoon. It is listed in my sig.

I am planning to add a shorter tube in front of my motor pod.

I've found a 25" diameter tube that I plan to shorten with the help of a fellow Iboater who is willing to shorten the length of the tube for what I think is a more than generous price.

I'm trying to come up with the best "theoretical" length to make the tube, since I can make it any length I want.

My motor pod sits about 4 1/2 feet from the rear of the boat, leaving about 19 1/2 feet from the front of the boat to the nose of the pod. I've read I should keep the rear of the toon forward of the pod by about a foot +/-. I have 24"o.c. cross members so 18' would be about the minimum I think I would go in order to catch the 18' cross member, but could leave some extra beyond that if it seemed like a good idea.

So basically I've got a range of about 18-19.5' of space to use.

My boat has 23" tubes, so the center tube will be slightly larger then the outer tubes.

Any input is appreciated. but don't try to talk me into a full length tube with the motor mount, etc. I 'm fully aware of what I'm getting into.

The magic distance is 7'
to 8' from the motor prop if you are going shorter. Personally I would add a motor transome to the third. I used 3 x 3 x 3/8 angle to attach the 3rd. Can be extended out and decked to stop spray.

 

[captmello]

Re: Adding a Third Toon, Ideal length?

The magic distance is 7'
to 8' from the motor prop if you are going shorter. Personally I would add a motor transome to the third. I used 3 x 3 x 3/8 angle to attach the 3rd. Can be extended out and decked to stop spray.

Thanks for the response, but the length has been chosen, for better or worse. the Toon is now back from being shortened and awaiting installation. I am about 6' from the the rear so we shall see. Fortunately my third toon is the same brand and will bolt up just the way it is without any added brackets or supports.

BTW, if you trailer, do you have a center bunk on your trailer to support the center toon?