Need your opinions.... Boat HP vs. Capacty

ksherbine

ksherbine

Active member
As most of you know, we recently took over the Classic Barnegat Sneakboxes. The previous owner made a great boat, but never bothered getting them certified with the Coast Guard, capacity tested, etc. He made hundreds of boats and most guys ran them with 9.9 - 15 horse motors and probably 3-400 pounds in them without ever having a problem.

We knew this was overrated though and figured a 5 horse would be more likely. We were shocked however to find that when doing the Coast Guard's calculations, if we rate it for a 5 horse engine, that will only leave us with roughly 230 pounds of capacity (person and gear). If we drop to a 2 or 3 horse engine we will have over 400 pounds of capacity (persons and gear).

While we're already working on either some modifications or a new model, in the short term this is our only choice. Since there's a ton of experience and wide range of hunting environments represented here on the Duckboat Page, I thought this would be a great place for some market research.

Would you think there would be more demand for:

A- a 5 horse boat with a 230 pound capacity or
B- a 2-3 horse boat with more than 400 pound capacity

Thanks for your help!

Kirk Sherbine
 
what would it take to get a 5hp with 400+ capacity? I would think a 5hp with 230lb capacity would knock out 90% of duck hunters...I wouldn't be able to get in it nekid! 2-3hp motors are hard to find at reasonable prices unless you find old Johnson and Evinrudes and love working on them..and most guys like to get to where they are going a lot faster than that. Can't remember what my MLB Zackbox is rated at..I use a 9.8 Merc, take my grandson with me and feel totally safe...course it's a small lake and river. I realize the ratings are a CYA type of thing too.
 
Kirk,

I'm 225lbs and my dog is 100lbs. Doesn't leave much for gear! I'd hate to get caught in rough weather relying on a 3hp motor to get me home too. Did the CG give you any insight to options for adding capacity and motor size. I believe the MLB Widgeon is rated for a 5hp. but don't recall the total capacity right off hand.

Good
 
Lee-

Our 14' model should fill that role of a 5 or 7.5 horse motor and 400 lbs. We're trying to find what niche the 12' model should fall in though.

I agree about the Coast Guard regs being a CYA thing. It's actually a 5x safety factor (if it takes 1500 lbs. to sink it, it's rated at 300 lbs.). But that's what the rules say so there isn't much choice.... Also, to answer your question the MLB boat is rated at 5 horse and like 250-300#. And you obviously know how it performs with double the horsepower and weight in it.

Also, we're looking at several modifications or options to increase the capacity, but don't want to sacrifice the history and tradition of the BBSB to do it. We'd probably offer it as a seperate model, then push this one for it's rowing ability (it's amazing how these displacement hulls row or get pushed with a trolling motor) and for smaller water. Although it's just a shame knowing that this design that's been around forever is relegated to that...

Thanks,
Kirk
 
on that boat is to increase its volume. It's always had way to shallow a transom for the motors that were being run on it, (and I was one of those that did). To get the rating up you'd have to raise the cockpit coaming, (that would get you a LITTLE, and also increase the volume of the boat by deepening the transom. Unfortunately that requires a new mold, or at least substantial modification to the existing mold. It could be done without destroying any of the excellent characteristics of the boat while adding safety and speed to the hull....

Good luck on whatever you do.

Steve
 
Kirk,

I am not familiar with the USCG calculations for capacity and maximum horsepower, but I assume that there are variables. I suggest you first re-examine the calculations and check for errors. Then, look to see if some of the variables you are using are too conservative.

According to the Duck Boat Specs page, the Duck Wrangler sneakbox has (had?) a generous capacity even though it is (was?) a displacement hull. Maybe there are ways to massage the calculations?

Back to your original question. I wouldn't consider a sneakbox if the minimum HP and capacity ratings didn't at least match the MLB Wigeon (5-hp and 374#).
 
Kirk,

I found the standards for backyard builders so I think I have a better understanding of the ratings now.

First, you didn't assume that the boat is a "jon boat" did you?

Second, what is the transom WIDTH on your boat? Did you measure gunwale to gunwale, or did you measure at the waterline?

Third, have you actually done the sink test?

I imagine the easiest way to increase the rating of the boat would be to maximize transom width. That would give you a higher HP rating and increase displacement.
 
We calculated it using the sink method (fill w/water and calculate how much it takes until it basically sinks, divide by safety factor (5 for 5 horse motor), etc). It's a lot more accurate and easier than any "measurement" method. I then got the guy from the coast guard to double check our calculations. He's the one that does the "official" test, so pretty much what he says goes.

I agree about either widening the transom or making it deeper. If we go that route we'll probably do a total rework though, which will take some time. We have a few plans in place, but first need to get this first boat underway so we can move on to the next thing.

Thanks again for all of your help.
Kirk
 
A- a 5 horse boat with a 230 pound capacity or
B- a 2-3 horse boat with more than 400 pound capacity

If those were my only choices, I would go with A. But then I only weigh 155 and don't hunt with a dog. I could get by with a 5 hp and probably keep the load to about 200 lbs. But back when I weighed 209, there is not way I could have done that. And most guys I see at the dock are probably pushing 200 lb & many have dogs. Heck, my hunting partner would exceed the weight limit with just himself & his gun, let alone add gas, shells, safety gear, decoys, etc... So a 230 lb capacity is really going to push a lot of guys out of the market IF they bother to read & obey the load limits, which is another issue all in itself.

While a 400 pound capacity would be great, with a 2-3 hp motor, would the boat have enough power to get out of it's own way? Not sure I'd want 400 pounds in there with only 2-3 horses to push me along. Get in rough water & you could get in trouble quick, even with a boat as seaworthy as a BBSB.

In the end, I would have to say that I would go with your 14' boat or I build a Devlin bluebill and put a 15 hp on it.
 
Kirk,

Carl makes a very good point. "[font=Verdana,Arial,Helvetica]So a 230 lb capacity is really going to push a lot of guys out of the market IF they bother to read & obey the load limits, which is another issue all in itself."

Around here your chances of getting a ticket for being over powered are much greater than for being over weight limit. Not saying that one situation is safer than than the other, just looking at it from the "am I going to get cited for this". Not too many DNR officers around here, are going to weigh your load unless you look grossly over the limit but they will check your horsepower.

You could market the boat as designed, rated for 5hp and less capacity, all the while explaining the Coast Guards safety margin. This way you can leave it up to the customer how much weight they feel comfortable carrying.
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Kirk,

Carl makes a very good point. "[font=Verdana,Arial,Helvetica]So a 230 lb capacity is really going to push a lot of guys out of the market IF they bother to read & obey the load limits, which is another issue all in itself."

Around here your chances of getting a ticket for being over powered are much greater than for being over weight limit. Not saying that one situation is safer than than the other, just looking at it from the "am I going to get cited for this". Not too many DNR officers around here, are going to weigh your load unless you look grossly over the limit but they will check your horsepower.

You could market the boat as designed, rated for 5hp and less capacity, all the while explaining the Coast Guards safety margin. This way you can leave it up to the customer how much weight they feel comfortable carrying. [/font]
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[font=Verdana,Arial,Helvetica]I agree with HD on this one. If it were me I'd much rather have a 5hp plate than a 2 or 3hp capacity plate. The rest of the load is nearly impossible to measure and I think very few tickets are ever written based on the load weight (unless you're hauling 6 guys in a boat built for 1 or 2 guys), but if the CG or CO's are going to check anything it will be the hp of the motor. Much rather be legal with a 5hp and be overloaded with gear than be required to have a smaller motor to be in compliance with the load. [/font]
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[font=Verdana,Arial,Helvetica]FWIW, I used to own a Fiberdome Bluebill that was 12' with a 5hp rating and it did fine with a huge load and a 5hp Merc/Nissan. It had a displacement hull so even the 5hp wasn't fast and I wouldn't have been happy if I was legally required to run a smaller motor on it.
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Last edited:
Perry-

You're right about the horsepower calculation, however a bigger horsepower boat reduces the available carrying capacity. Our boat can easily be rated for a 5 horse, but then the load has to be reduced to 230# or whatever to compensate for the heavier motor and extra safety factor (CG regs use 85# for a 5 horse).

Brett/Dave-
You bring up a good point about the regs. It would be easier to get caught with a tag marked 2 horse than one marked 5 horse.
On the other hand, one of my reasons for jumping through all of these hoops is so somebodys widow doesn't sue me 10 years from now because her husband did something dumb in one of my boats. And telling them officially "ignore this tag" would go against that. I actually had a long talk with MLB Mark the other night about the same subject, and he's of the same mindset.
I do see your point though that HP is probably more important that weight in a lot of instances.

This is a tough one! i'm 99% sure that we're going to push the 14' for "motor hunters", and push the 12' boat for the thousands of guys hunting reservoirs, marshes, etc. where rowing is best. In the meantime we're going to start working on modifications to the 12 footer.

Thanks again guys. This site is great!!

Kirk
 
I think 3 hp and 400# is better. I would only be able to take myself and gun at 230#. What about 4 hp?

But is it a planing hull anyway? Can you sandwhich some kind of spacer between the top and bottom to gain an inch or so of hull depth?
 
Someting doesn't sound right. What is the width of the transom and the lenght of the boat? My sneakbox is 11' 10.5" long with a 42 inch transom. it is rated for a 7.5 HP motor with a total capacity of 370 lbs. The transom is 13 inches tall. My boat is rated by the USCG at Soloman's Island.
 
Tag it like this;


230lb load @5hp
400lb load @3hp

That way you can at least advertise it as able to hold "up to" 5hp.
 
Lee-

That's a great idea. I'll call down to Soloman's boat test station and see if that's kosher to have a "dual certification".

Also, sandwiching a spacer between the deck and hull is a good idea as well. Especially until we get a chance to either re-work the mold or make a new one. And to answer the question, it's a displacement hull, not planing.

Thanks again guys.

Kirk
 
I doubt you could have two certifications on the same boat, in could be too complicated, but maybe customers could choose one or the other when it is purchased new.

You should find out how close the hull demensions are from getting an increased rating.
 
I agree Andrew. I was thinking more on the lines of get it tested (and passed) both ways, advertise it both ways, then let the customer decide which sticker to put on it.

Thanks,
Kirk
 
Kirk, Did you getmy PM? What part of PA are you in? I get up that way from time to time.
 
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