A question for you guys that have built BBIII's

Cody Williams

Cody Williams

Well-known member
Hello everyone, just had a quick question for you guys that run BBIII's. How deep does your hull draft with a hunting load? I have the plans for the BBIII and I'm kind of surprised at the amount of V designed into the hull. I'm thinking of making a few changes to produce a shallower running hull in the rear, I'm planning to move the transom to the rear of the sponsons, remove all rocker from the rear of the hull and possibly decrease the amount of V in the rear 2/3 of the hull by an inch or 2. Seaworthiness isn't really a concern as I'm never faced with more than 2 foot waves at the maximum and most water that I hunt is pretty shallow so I'm looking at having the shallowest drafting hull possible. I know there are other designs that are more optimized for shallow water but I can't get the BBIII out of my mind, something about the lines of that boat just speaks to me. Thanks for your input guys!
 
With two 200lb men, two dozen plastic decoys, 100lb dog and "stuff" my BBIII needs 12 inches of water to run a prop outboard on tilt. I can run in 10 inches of water, but the prop becomes a mud motor which is not good for the impellar life span.

The V in the stern is not an issue, but the deeper V up behind the bow is where it hangs up on the mud and other debris.

If you are really going to be running shallow spots most of the time I would look at a flat bottom boat like one of the "fast" garveys designed by Bateau and then flatten what little rocker is there out. Cut the side height down and then deck the sides like the BBIII and you are good to go.

If you try to do this with a BBIII why even buy plans since 90% of them won't be used in the build. Start off with a design that already has most of what you want.

And use a mud motor. A long tail works better to get your boat out of the muck than a short tail surface drive will. You can't jam a short tail down into the muck and use it to walk the boat out. I have used a light weight 7hp stumpjumper long tail on my BBIII and it works OK, just slow pushing all that water, but it will push the boat through deep muck that only has 2 to 3 inches of water on top of it. Slow and messy, but moving without having to get out of the boat and get stuck up to my waist in muck.
 
So you're saying that you can go through the skinny stuff in your BBIII with a longtail? I currently run a 13hp longtail on my jon boat and that's what I'm planning to power my BBIII with. I know there are better designs for mud and shallow water but I'd be OK in 90% of what I hunt if I'm only drawing 8-10 inches. My desire to modify the BBIII is mainly to take whatever rocker is in there out, if the V isn't an issue I will leave it alone.
 
With the 23hp long tail, I would move the transom back to the stern and then make it higher so that you will have enough room to lift the motor out of the water as well as spin it around for trailering.

And yes I have successfully used a 7hp long tail to push a normal BBIII through saturated muck with only 2 to 3 inches of real water on top of it. Its really about two feet of water that contains about 80 percent rotting vegetation, which once compacted acts like mud and causes the boat to drag.

The boat was still drawing water and was not getting up on top of the muck very much. The deeper bow keel area was dragging as it compressed the water out of the muck and kind of sticking. However, the little long tail was able to push the boat bow out into more open water and we jumped through the rough stuff without getting out of the boat.

There in UT I am guessing that you are hunting typical great basin tule marshes where you have a reasonably hard clay/silt mud bottom and then tule rafts. You don't normally have a mud issue unless the water drops too far, and you don't have thick organic rotting vegetation mats to work through. I grew up in Fallon NV and am familiar with the Stillwater and Carson Sink marsh systems and am assuming your UT marshes might be similar. If they are, your main concern would be supporting the weight of the 23hp long tail. So a wider stern would help that as well as beefing up the transom.

If you have areas that you have only 2 to 3 inches of water over a firm mud bottom, the deeper bow keel area will be hard aground and you will go no where. You will need at least 10 inches of water to keep the front keel area floating depending on your load.
 
Thanks for your advice Ray. You are spot on about the marshes here in Utah, there are a few spots of bottomless mud but for the most part the bottom is fairly firm with a few inches of mud on top. I run a mud motor because most of our marshes are too shallow for an outboard but getting stuck usually isn't too much of an issue. I think I will leave the V alone and just work on moving the transom aft and beefing it up a bit! Thanks again for your advice.
 
Cody,
You got really good advice. One thing I will add and i am sure you already know this. Mud motors really are designed to run on flat bottoms so you are compromising by using the BBIII. If you need the design of the BBIII for some open water i can understand making the compromise but if big water is not an issue you might want to reconsider.

I built a BBIII first and then built this boat. Its more of a spoon hull. takes waves well but still slips into the skinny water. Garvey's can be pretty too! I now run it with both the 40hp outboard and a 35hp surface drive when in the marshes.

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That's a fine looking boat Brandon! That thing must fly with a 35 surface drive on the back, do you even touch the water? I'm looking at a mix of open and shallow water use for my boat, so I love the BBIII hull but I would be well served by a more flat-bottomed hull also. Looks like I might have to build 2 boats!
 
Cody, I get where you are coming from as far as wanting the lines of a BBIII and wanting the performance characteristics of a flat bottom. I've been thinking about how you could make your own flat bottom BBIII and wonder if this woudl work.

1) loft and make your 2 hull bottom panels out of scrap wood like luan. They wouldn't need to be scarfed, just use a luan butt block screwed.
2) loft and cut the side panels out of good wood. When you loft the side panels exaggerate the height by a couple/few inches. You need to do this to maintain the side profile, since you will loose the bouyancy of the "V" that you are eliminating. This is very easy to add height.
3) stitch together as if you are building a "V" hull as designed.
4) install bulkheads with flat bottoms (epoxy bulkheads in to sides).
5) flip and remove "V" bottom
6) install flat bottom and trim to fit sides
7) stiffen flat bottom with something (stringers or core it).

This woudl allow you to build without winging it since you like the lines of the BBIII so much. It really wouldn't take much longer (steps 1-3 are the wasted steps and they take a day max and the cost would be less than $50).

The big concern I have is that I don't know how to replace the strength you would loose in taking the floor out. The plywood woudl have to be thicker than the 3/8 specified or you would need a core or stringer system.

Some woudl say that this a half-ass way to get what you want and it woudl be "almost" easier to design from scratch. I agree that there are steps wasted in there, but at the same time the cost and effort for a novice to design a boat with nice lines would be pretty high if possible at all.
 
Thanks for your advice Tod. I was actually thinking about doing something similar to what you described, I don't think I would totally remove the V but I think reducing it by 2" or so would be a good compromise by allowing you to keep the strength of the V'd keel seam but allow for a flatter bottom. If I'm thinking correctly, if you reduced the V by 2 inches at each bulkhead (or removed 2" at the stern, and then calculated the percentage of the overall height that 2" is and apply that percentage to every bulkhead) could you add 2" to the sheer line of the side panel and end up with roughly the same hull shape, but with slightly taller sides? I'm thinking an experiment with a scale model is in order.....
 
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Thanks for your advice Tod. I was actually thinking about doing something similar to what you described, I don't think I would totally remove the V but I think reducing it by 2" or so would be a good compromise by allowing you to keep the strength of the V'd keel seam but allow for a flatter bottom. If I'm thinking correctly, if you reduced the V by 2 inches at each bulkhead (or removed 2" at the stern, and then calculated the percentage of the overall height that 2" is and apply that percentage to every bulkhead) could you add 2" to the sheer line of the side panel and end up with roughly the same hull shape, but with slightly taller sides? I'm thinking an experiment with a scale model is in order.....
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I don't think that would work or at least I can't get my mind around it. The was the designs work is that the skins define the shape and the bulkheads follow the shape defined by the skin. The bulkheads are fit to the shape once the hull is stitched and spread to proper shape. In fact, many of us don't even use the bulkhead measurements as provided, tather choose to pull the masurements ourself from the spread hull to get a better fit.

T
 
Why start with a BBIII and change everything below the waterline? Isn't that part that does all the work? Why not find a proven boat plan that already has the flat bottom shape and then change the upper section to suit?

The decks and combing can be designed by eye, but the hull shape will effect safety if not properly aligned. What about a 'flats' type boat design?
 
Why start with a BBIII and change everything below the waterline? Isn't that part that does all the work? Why not find a proven boat plan that already has the flat bottom shape and then change the upper section to suit?

The decks and combing can be designed by eye, but the hull shape will effect safety if not properly aligned. What about a 'flats' type boat design?
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Because he likes the look of the BBIII.
 
Tod, I understand the panel concept (at least on paper), so I think my next step is to build a couple of paneled half models like Devlin details in his book and go from there. I'm thinking it will work out, but I would like some physical evidence before I start cutting up $100 sheets of plywood!
Andy, it's basically because everything else about the BBIII works for me (outline, capacity, profile, width, etc.) and also because I like a challenge and by all evidence I'm a lifelong advocate of making things more complicated than they need to be!
 
I like a challenge and by all evidence I'm a lifelong advocate of making things more complicated than they need to be!
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That is 2 good reasons, plus the pride in a job well done.
 
I can get my BBIII in some pretty shallow stuff just the way it is, not quite knee deep in the picture and we motored into the millet till it cloged the prop up. I have poled it in water to shallow to run the motor several times and when it gets to shallow to do that I have gotten out and pushed a time or two. Never really paid attention to the depth but it seems that if there is water it floats pretty much.

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Cody

One thought I had was to build the boat per plans. After the fillets are complete and before glassing flip her over and cut the bottom out to reduce the draft to your liking. Then fit a new piece, something I'd imagine would look like a fat waterski and glass it in. You could remove several inches of draft without taking that much out of the hull I'd imagine. Another option would be to pay Sam to design a flatter hull with he top profile of a sneakbox.

Eric
 
Craig-that is the kind of info that really helps out, maybe I don't need to modify it as much as I thought.
Eric, I have actually talked to Sam about this idea and he offered to make a new design, but he also seemed to think that I would be OK with the hull as it is. The more I think about this the more it makes sense to stick fairly close to the original plan, although I'm still planning to remove all rocker from the rear and move the transom aft. Thanks again everyone for their insight!
 
Cody, I was going to tell you the same as Craig that I have had mine floating in fairly shallow water. Below my knee as he said. So your plan may not be all that far off. Taking the rocker out will make the boat a lot less sea worthy in big water but still safer then a john boat of similar size.

How you you plan to get the rocker out of it? I could do it in a plank built boat but stitch and glue would be harder to figure.

Oh and that boat I posted before does not fly as much as you would think with a 35 surface drive. Speed is around 22 mph but those motors are not built for speed. Now with a 50hp tiller she screams!!! To bad I have a 40 for her.. the 50 was borrowed.
 
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