# The Great Sponson Debate



## swampfox (May 9, 2007)

In theory/reality a boat with sponsons while at rest will draft less. Than the same boat/length with flat transom. Now here is where I think most people including those that actually build the boats get lost on this. And this applies to us guys that use smaller motors especially. If you weigh more than your motor. Then a sponson boat should draft more WHEN POLING. And this is when you need the least draft. A six inch draft isn't doing me much good while motoring down th ICW. I want to skinny when on pole. This is because nearly all builders(like my HB and my old ECC Lostmen) have the platform over the huge gap in displacement. You literally are losing a full third or more of displacement on most sponson boats. If you are directly above the motor. Then the advantages of the sponsons are greatly reduced. This may be more of a concern to me. Because I am built like Rob Fordyce. Maybe not so swollen ;D. So what I am getting at is it doesn't make sense to move a 120 pound tiller forward. And then leave a 230 pound man hanging off the back with only 2/3 of the boat to support him. Of course on bigger engines that will weigh 75-100 pounds more than most guys. You will get a advantage. So keep this debate in the fame work of small boats and motors. Personally I think a flat transom with a platform forward design will draft less in most circumstances. And you don't have the drawbacks of sponsons. On a side note I do really like the rocker in my HB hull. It really helps handling and getting the nose up in nasty stuff. That was something I hated about the Lostmen. I couldn't get the nose up on it for shiat. This is one of the draw backs to sponsons. But Morejohn's design skill seems to have worked around that issue. The guys at Maverick are about the only ones that have honed in on this. They had some small platforms in front of the motor. This takes full advantage of the sponsons. What do you guys think? :-/


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## Brett (Jul 16, 2008)

Pole from the bow, balance that hull better.
We don't need no steenkin platforms.


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## CurtisWright (May 9, 2012)

"Now here is where I think most people including those that actually build the boats get lost on this. "

Just an FYI, Builders dedicate their lives to understanding these arguments.

Moving the motor forward moves the center of gravity forward. Sponsons move the center of buoyancy forward. but not as far as the COG. The lack of buoyancy at the transom due to sponsons on a Lostman at 6" draft is ~50lbs.

I am a licensed PE.  I have studied naval architecture at the college level and I have designed and built two boats.  Plug, mold, hull and all.  One of them was vacuum bagged.  

There are some pro's lurking on this sight that school me on just about every bragging spot update.  Before they catalyze the first gallon of resin they know the type and size fisherman they are building for. They know the fish they will catch and they know the water they will catch them in.


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## devrep (Feb 22, 2009)

I don't get the "standing over the gap between the sponsons" thing. So if you're on a catamaran is it going to sit lower when you stand in the middle than if you are standing to one side? Certainly having the platform further forward will make a difference in how the stern squats when you are poling. My platform puts me out beyond the transom but I do like the extra room on the stern.


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## swampfox (May 9, 2007)

CW I agree with most of that. But I don't really think these small skiff builders are naval architects. Nor can they hire one for a year as they produce prototypes. It's just not in the budget like bigger builders. You even stated "some" have this figured out. 

DeVrep you gotta keep this in the frame work of small beam, short length and small light engines. It's not comparable to multihull cats or even bigger skiffs. 

My whole point is sponsons on little skiffs as setup by most builders. Seems counter productive. It's like they took a feature that worked well for the bigger boats/engines. And scaled it down to the TPS/micro size. And that placement of the person overrides placement of a 120 pound tiller. DeVrep referenced it as "squat". That "squat" is more draft. Hell the sponsons were kinda a happenstance design on the Bannana River skiffs. They were added to make the ass end float when they pushed off the bank into the water. Not even thinking about flats fishing. It's was just some old cracker trying to work smarter not harder in the Florida heat. Now they are standard on most flats skiffs. And I bet he wasn't a Naval Architect.[ch128540] Hope this is kinda making sense outta my thought process.


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## swampfox (May 9, 2007)

Devrep what boat do you have? Sounds like they have it setup right. But my HB has me behind the transom. Do you kinda see the point I am bringing up now? Remember the skiffs in the 80s/early 90s. They all had the platforms angled behind the transom. Well nobody does that anymore thankfully. And it's for the same reason I am referencing. Now let's take my HB. Even though my engine out weighs me at 248 pounds. I can pick up more draft if I redesigned my platform to get out over or in front of the transom. Then I would be taking full advantage of the transom. But that would be in the way on the back deck. Unless it had a extreme curvature from the back to the front.


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## swaddict (Dec 19, 2009)

That's the reason I had a platform built that was in front of my transom for my 17T. Granted it's not a technical poling skiff, but with the original platform angled towards the back I was always on the very front edge of the platform. It feels better when poling with my weight in front of the motor.


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## swampfox (May 9, 2007)

Exactly! Now imagine if a big 2x3 center section of your transom area was removed with your old platform. Body placement far out weighs small motor placement.


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## el9surf (Dec 23, 2008)

Once you get an angler up on the bow the boat balances out sponsons or not. If the platform is too far forward you lose deck space and potentially interfere with poling. I have had skiffs with and without. Seems like the added buoyancy helps to maintain float with a heavier power option. Pros and cons both ways.....


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## permitchaser (Aug 26, 2013)

My poling platform is over the transom and if the motor is straight down I would be over the front of the motor, but I pole it with the motor tilted up so I would be over the motor. I thought the Sponsons helped with draft. And if your not over the motor its harder to pole

My boat was built in "97. It has a splashed Maverick hull. I don't really know how it poles because I have only poled it in a 30 mph wind. I hope I get another chance in 2 weeks when I'll be on some flats in NC

I have no illusions that I have a technical skiff

Wondering if it would be better if my toes were over the front of the platform when I pole


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## swampfox (May 9, 2007)

EL9surf I see were you coming from as it feeling good balance wise. That's probably why most of us haven't gave it much thought. But these small skiffs are designed and built from the start to be stupid skinny. And are advertised as such. Even to the point of some possible exaggeration on the builders part : But then they go with some platform placement that not only doesn't take full advantage. But could even add to the draft. I'm just getting technical as far the loss of displacement/leverage/man vs. motor weight.


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## copperhead (May 30, 2008)

Is the glass half-empty or half-full? 

I see the point you are making, but let's just say you have a skiff that is 16' long and you are perfectly happy with the draft, small outboard and poling platform configuration and it fits in you garage nicely.  OK? 

Well were I to add sponsons to your skiff, it would still fit in the garage the same, draft less with you on the platform, plane off better with the outboard and probably pole better because the effective waterline is now longer.  Get my point?

Were I to now "fill in the sponson space" it would be a  17' skiff flat transom, it would do all those things just as well or better, just wouldn't fit in the garage now...

I can give many reasons why or why not to have sponsons on a skiff but there is only one real point to make.   You just don't just add sponsons (or take them off a hull, fill in the space or whatever), you just don't add tunnel inserts in a mold, etc, for the best possible design.  The designer has to include all these types of elements in the design from day 1 to make the best skiff possible, including whatever features they feel are most important for what they are trying to accomplish.

Just my opinion of course....

Thanks!

M


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## swampfox (May 9, 2007)

Permit yes sponsons will help with draft in most cases. You are just behind the transom and that's fine because that 140 is a 410 pounds. And your boat is big so the effect is minimal. Nothing like say the effect on a Glide or Glades skiff. Y'all gotta think small on this. Ironically both of these small skiff/power plant set ups have flat transoms 


Copperhead you are right on those points. But you are completely missing mine.  And there quite a few skiffs out there that did just what you described as far as just adding sponsons.


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## Jared T. (Apr 13, 2014)

Won't sponsons aid in taking off/hole shot?


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## permitchaser (Aug 26, 2013)

Thanks Swamp. I think my boat drafts 8-9" but I don't care so far I have not had any problems. Even if you draft 6" you still need to get off a flat before the tide goes out too far. I like my sponson I think they help with my take off and there great to stand on when nature calls


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## CurtisWright (May 9, 2012)

> Is the glass half-empty or half-full?
> 
> I see the point you are making, but let's just say you have a skiff that is 16' long and you are perfectly happy with the draft, small outboard and poling platform configuration and it fits in you garage nicely.  OK?
> 
> ...


Boom! 

To answer your question the glass is twice as big as it needs to be. Could have saved some weight with a better design!


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## Capnredfish (Feb 1, 2012)

There is no debate. Skiffs with sponsons just look cooler and fit the garage better.


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## Thomas1 (Oct 20, 2011)

Same boat length and weight - sponson boat drafts more due to less bouyancy. You are all giving builders and designers too much credit. Most of them build the mold, pop out a boat and hope for the best. Then they tout the benefits of their design even though there was no R&D. R&D is not going fishing in a half built hull you popped out of a new mold, it is building a working boat to scale and refining it prior to making the mold.
So far, Chittum and some Hells Bay hulls are the only ones to do this.


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## fishicaltherapist (Mar 9, 2013)

There are pros & cons in EVERY design and type of anything that floats, IMHO. WE are SO fortunate to have personal choices. NOW, I have to go to bat for Copperhead.....check out his design/engineering background, integrity,quality/price of his skiffs, and customer service. [smiley=2cents.gif]


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## Sandalous (Oct 30, 2013)

> ... and probably pole better because the effective waterline is now longer.


With all due respect, I believe that that is incorrect. Longer does not mean better to pole. Longer means more surface drag area in the water, more material weight to push, more side area resistance when attempting to spin.

Case in point, 16 and 17.8 whipray. One of the only true examples of 2 hulls that, for the most part, only differ from having sponsons added on.. Ask anyone who has spent time on both of the hulls, which one is a better *poling* skiff... If they don't say 16, they haven't spent enough time on one. 

Sponsons are added to provide extra buoyancy and length in the stern of the boat, to float and plane larger motors / more passengers, end of story... You lose the ability to spin quickly and pole as efficiently as a shorter boat. There is a reason that many guides fish a 17.8... They normally need room for themselves and at least 2 clients and gear, which is tough on a 16.

That being said, I have always been really surprised by the amount of people out there who rarely fish more than themselves and another person on the boat, and have 17.8's instead of 16's. More or less same speed relative to horsepower, more or less same ride, easier to push, easier to spin.


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## Megalops (Oct 23, 2011)

So....the SUV14 and Shipoke 14 pole better than the 16ft whip?

The comment about HB and Chittum being the only skiff manufacturers to do r and d is ludicrous. East Cape? Bohemian?


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## el9surf (Dec 23, 2008)

I think he was referring to tracking better. A longer boat typically tracks straighter on the pole when compared to a shorter hull. The shorter the water line the quicker they come off center line. The longer the water line the better you will span a chop as well.

Personally I have the 17.8 and have no issues poling or spinnining. It had been one of the easiest boats to pole that I have ever been on. I have had several 16 ft non sponson hulls and they do spin easy, but trying to pole straight takes a lot more corrections, especially in wind or current.


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## swampfox (May 9, 2007)

Let's take a tiller Caimen with a Rude30. One of my all time fav skiffs.

Caimen is just shy of 18 with about 62" beam. The lower measurements are what matters most. But we can just use what we have for now. The Evinrude30 tips the scales at 150. The average American male is now 192! You fat bastards ;D now the main problem with tillers and platforms is clearance. So ECC like everyone else has the platform in the rear for this reason. So you have a 200 pound man hanging off behind the transom like in the 80s. To get a 150 pound motor forward 22 inches or so.  Wouldn't it make sense to move the larger mass forward and have the smaller mass in the rear? Which is what you have with the full displacement of a flat transom. ECC seems to think so. Because on their remote steer Caimens they will have the platform well forward if not completely forward of the transom. That's is because the benefits grow exponentially every inch forward you can get the weight. When you have all the mass of man/motor hanging off the back it's a leverage effect. Most of us know this as squat. Well when you have squat you are adding draft. Just like a tunnel will draft more than a flat bottom of the same boat. It's because that empty space called a tunnel has no displacement. Just like that big empty space under most platforms. You lose about 1/3 of displacement with sponsons the last two feet or so. And it's were you need it the most center/rear. My thinking is that with a motor 150 pounds or less. You are better off draft wise with a flat transom with a platform putting the person forward of the transom. You can't think of this as "adding" but rather "removing" displacement from the hull. Because it remains the same overall length. So you are removing a portion of the hull to move the engine forward. Of course hull design has a effect how this works when a person is on bow. The Ciamen it has a very sharp entry. That doesn't gain displacement until it's level and deeper in the water. Where the wider part of the hull is in the water. Where say a boat that was flat like jon boat will have full displacement all the way to the front. 

Again once you get into 50/60hp motors and up its a wash or is a benifit to draft with sponsons. Got to think small here. I not trying to debate pros and cons of sponsons in general. There plenty of each.


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## East_Cape (Jun 3, 2008)

Like all our boats; a customer can have a boat built the way they want…
So poling platfroms are most of the time mounted over center of the transom. Meaning "center of hoop" is center of transom. However we also mount poling platforms with the back of the platform inside & in front of the transom. Pics/videos of this are on the website. My new EVO has the platform in front of transom. But the two next to mine want the hoop behind the transom as they deep water pole a lot and draft wasn't a concern to them. Also why they have a 115hp and I have a 60hp on mine. 

Also a Lostmen can run bow high as we have pics/vids showing this. Motor height/prop/and power will always come into play on performance and attitude on any boat.

I'll comment on "sponson vs non" as they each have a pro and a con to each  IMHO…

Lastly, when we came up with our 3-sided vented tunnel we made a few hulls to do R&D and once we perfected what we wanted to offer, we than made a "drop-in" mold of it to be placed in two of our models. For us mold storage is an issue and to have two molds of the same boat with only one having a tunnel and other not didn't make sense to us… So, hence the drop in effect. 

Tight lines and carry on guys!
K


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## Sandalous (Oct 30, 2013)

> I think he was referring to tracking better. A longer boat typically tracks straighter on the pole when compared to a shorter hull. The shorter the water line the quicker they come off center line. The longer the water line the better you will span a chop as well.
> 
> Personally I have the 17.8 and have no issues poling or spinnining. It had been one of the easiest boats to pole that I have ever been on. I have had several 16 ft non sponson hulls and they do spin easy, but trying to pole straight takes a lot more corrections, especially in wind or current.


My comment is related directly to the overall poling capability of two boats, of equal beam, and same main hull design (aside from sponsons), with different lengths. Sure the longer boat is going to track slightly better, in slick conditions, but the shorter boat will be far easier to get moving, control, and spin. Simple physics.

Does the back end of your pro slide out on a down-wind angle, and does the nose want to point right into the wind when you are poling an upwind angle? I am interested to know, because I have been on many 17.8's, old and new and they all share this trait when the wind is over 10kts. Sliding to the point of having to lower the gearcase into the water to dampen the slide. It is one of the very few curses of a modified V design. However, I have found that this does not happen anywhere near as severely on the 16 because there is less flat ass in the water to slide out / the tower is closer to the pivot point (V at the bow) / there is less hull side to catch the breeze / the V makes up more of the overall hull length.

While we're on the subject, I would also like to know how you think the 17.8 spins in calm water in comparison to the 16.

On another note, since when did everyone get a hard on for doing all of this straight line poling? Last time I went fishing, I needed to spin the boat to make a shot at a fish a lot more than I needed to pole in a perfectly straight line.

I'm not here to knock anyone's boat, or opinion. This is a debate, right? They all catch fish, and they are all beautiful in the eye of the beholder, which is all that really matters.


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## copperhead (May 30, 2008)

Let's try a different point of view, with a bit of math thrown in.   Were I to take a sample skiff with sponsons and fill in the sponson area to give better support, what are we really talking about?  So let's say the sponson is about 1' long, draft on the hull is 6" (for ease of math) and we have the motor mount area is about 22".  Fill in the sponson area and we gain about 56 lbs more of bouyancy.  Not a huge amount.  Take your battery out of the transom area and move forward and you accomplish the same thing.  

As far my comment of adding a bit of length to a 16' to pole better, I was talking in general, not a mfg's specific model(s).  But I will say this, for a truly optimized poling skiff, it is my opinion that somewhere at 17' (+-) seems to be the ideal.  The 16 spins better, lengths approaching 18 track better, 17 hits the best compromise, _all given the same length / beam ratio_.  This is all relative to the normal water and wind conditions where you fish tho'!

M


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## swampfox (May 9, 2007)

Copperhead you really need to do a full calculation on the entire boat to get accurate. It takes the boats length and weight into equation. But with the simple buoyancy math you used. Many sponsons are twice the length at about 22-24" range. So you can just about double the results you came up with. Which would be around 100 pounds.


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## Sandalous (Oct 30, 2013)

> But I will say this, for a truly optimized poling skiff, it is my opinion that somewhere at 17' (+-) seems to be the ideal.  The 16 spins better, lengths approaching 18 track better, 17 hits the best compromise, _all given the same length / beam ratio_.  This is all relative to the normal water and wind conditions where you fish tho'!
> 
> M


I see where you're going with this. And I too prefer a 17 with a square transom as a good all-around boat. However, 3 different-length boats of equal length/beam ratio and design should all pole exactly the same in terms of tracking/spinning, only requiring more or less pushing effort on the pole relative to size. Will the 16 come off course faster than the 18? Possibly, but this is more of an issue of a poor hull design than a difference of 2 feet. The hull should not want to come off course at all in the first place.


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## Thomas1 (Oct 20, 2011)

Not trying to hurt any feelings with the R&D comment. If the first time the builder rides in a hull design is the first boat out of the mold, there was no true R&D. One can argue degrees, lessons learned from previous models, years of experience etc. The fact is there was no testing done and the boat is what it is now unless redesigns or mold changes are done.


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## WSK (May 15, 2015)

Wow . I pole my grown son and his friends around all day on my Lostmen NO problem. I really enjoy watching them catch fish and the bantering back and forth on the front deck. At 62yoa not a problem on a Micro Skiff. They do let me take a lunch break and no pushing across sand bars.


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## Megalops (Oct 23, 2011)

tommy1 you're not hurting any feelings.   just disagreeing with you. Maybe our interpretations of R and D are different? That's all.  I just find it hard to believe that HB and Chittum skiffs are the only guys that do R and D when you have all these to consider:  East Cape, Maverick, Aeon, Dragonfly, Bohemian, Spear, Ankona. Skull island.


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## swampfox (May 9, 2007)

Not to derail into a R&D debate. But if any of you guys followed the Chittum build. They spent I think at least a year with naval engineers a 5axis mills building the prototype to within 1/1000th. Only to hack it up and make changes because it didn't do exactly what they wanted. Sure all that time and effort got em very close to what they wanted. It still took seat of the pants real world engineering. :-?
On a boat as simple as these small skiffs are. I think someone of average intelligence with a calculator, paper and pencil. Can get very similar results without dumping six figures and a years time into a prototype. These are not complex racing sailboats or something. They are all pretty much pointy in the front and square in the back. With a modified V transitioning to a flat bottom.


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## WhiteDog70810 (May 6, 2008)

I guess I don't see the debate here. Sponsons are just a compromise, as many have already mentioned. The benefits and drawbacks are pretty much common knowledge. It goes without saying that they impact performance and therefore should be well thought out, not just bolted on any old hull based on a whim. Fortunately most small skiffs are fairly simple creatures and many can do the necessary math to make a good boat without extensive R&D. From what I've seen, Chittums are not simple creatures, so I can understand why they do as much R&D as they do, but I also cannot afford a Chittum, so that R&D is meaningless to me.

Sponsons allow a X" wide transom to support more weight at the transom a given draft; nothing more, nothing less. Sponsons allow a smaller boat to handle a heavier motor while still fitting in your garage. If that is one of you requirements, they are helpful. Obviously, you could get a longer hull and skip the performance drawbacks, but then it wouldn't fit your garage and you'd probably just carry more crap/friends, thereby requiring more power and a bigger motor and negating the benefit. 

One drawback that is never mentioned is that sponsons are always right where you want to place the foot of the pole, so the platform is often shifted aft to compensate. Within reason, the impact of the weight of a man on the poling platform on the draft will be affected by the overall balance of the hull more so than the specific location of the guy relative to the transom. If the hull is loaded to float level and there is another guy forward, the hull will still float pretty much level. If the guy on the platform is fishing alone, it is very unlikely there is enough weight forward in any microskiff to keep the hull level, so the transom squat will significantly increase draft and poling will be affected. When fishin alone, listen to Brett and stay on the bow.

Nate


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## Thomas1 (Oct 20, 2011)

Of all the bigger name manufacturers in the skiff world, who and when was the last time a skiff design was made with sponsons?
Seems they are all departing from them on new models, but will not speak poorly of them because of the majority of their catalog cites them as a "feature".

Just an observation.


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## swampfox (May 9, 2007)

Tommy that's one of the reasons I started this. There is a definite move away from sponsons as of late. Just trying to get a idea of everyone's thoughts on em. I think they are a advantage for the bigger engines. Not so much when you out weigh your motor by a hundred pounds. Then I feel you are better off draft wise. To move the person forward and forget the motor. Of course the best would be sponsons and have the person forward as well. Then you would be taking full advantage of the sponsons. But that doesn't work well for most layouts. It's more than just leveling the boat. That helps of course. But if that's all it took we would all have tunnels. All things being equal you lose more displacement with sponsons than most tunnels.


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## Jim Lenfest (Jul 20, 2016)

Brett said:


> Pole from the bow, balance that hull better.
> We don't need no steenkin platforms.


That was what I was wondering, why not pole from the bow. Where I live, I just try to get into a spot before the tide leaves. Once in a while, I might shove the boat in over a mussel shoal with an oar, but with the tide dropping at 3 feet per hour sometimes, there is just too much current.


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## Str8-Six (Jul 6, 2015)

I’m not a rocket scientist or anything but doesn’t adding more weight(sponsons) increase draft? Yes it also adds buoancy which decreases draft but it is probably negligible in regards to draft difference because of increased weight. The poling platform forward thing sounds like a good idea but also decreases deck space. I say just move a battery(s) forward to balance skiff and go fishing. 

Mosquito is new model and has sponsons BTW.


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## Capnredfish (Feb 1, 2012)

Repeat. You guys can keep going at it. Sponsons look cooler and fit the garage better. With or without catch fish.


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## Jim Lenfest (Jul 20, 2016)

I believe sponsons keep a boat from porpoising as much. In my mind, they are like a non adjustable trim tabs on either side of the motor, which they also serve as more storage or flotation since they are all closed in. While adjustable, the trim tab provides no flotation whatsoever.


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