[fpjeepy]

Kind of different than most boats discussed on here, but I was wondering if anyone else would have any interest in a boat like this...

Basically, I want a boat that I can run 5-50 miles offshore for bottom fishing and tuna fishing, but I don't want to spend a lot of bills on the boat, nor a lot of bills on the fuel. IMHO most of the used boats on the market are not fuel-efficient. Because they were once a new boat, and a guy spending $100k on a new boat, doesn't care about saving $20 in fuel. So boat design is driven mostly by people buying new boats. People with $$$

So I'm thinking a 25-30ft x 54-60" beam. 50hp outboard, t-top side-console. Semi-displacement hull. capable of 16-knot cruise. 24"+ gunnels. Self-bailing (self-rescuing). I'm thinking aluminum because it doesn't require a mold, and is cheaper than cold molding.

To everyone in the developed world, this sounds like a crazy idea, excessively out of the ordinary. But many watermen of the developing world work every day on low horsepower canoe or panga style boats. To them, I think this would be the super deluxe model.

 

[bryson]

Not a bad idea -- looks like a small pilot house on a Panga style skiff. 54-60" would likely feel pretty dang narrow on a boat like that. It's hard for me to think about how stable it would feel when adrift/anchored/trolling in heavy seas. It could be fine, but I don't have much to compare it to.

I also would think full planing hull would be more efficient, and you could get better speeds. 50 miles is an awfully long run at 16 knots.

I don't know how much of a market there is for a boat like that since it would be pretty specialized, but it would definitely be a cool project for a one-off.

 

[sjrobin]

Pacific or Indian Ocean. Not G of M or Atlantic.

 

[fpjeepy]

Not a bad idea -- looks like a small pilot house on a Panga style skiff. 54-60" would likely feel pretty dang narrow on a boat like that. It's hard for me to think about how stable it would feel when adrift/anchored/trolling in heavy seas. It could be fine, but I don't have much to compare it to.

I also would think full planing hull would be more efficient, and you could get better speeds. 50 miles is an awfully long run at 16 knots.

I don't know how much of a market there is for a boat like that since it would be pretty specialized, but it would definitely be a cool project for a one-off.

I drew up a few models, the pilothouse version was the only one I could find on my laptop.

It would definitely need some extra bits to feel stable. Rocker stoppers and or sea anchor at drift and maybe some z-wing downriggers at troll. And even with those, it would never be as comfortable as a boat with an 8ft beam, but that is a sacrifice you make to save some fuel.

And a boat designed for semi-displacement will be 2-3 times more efficient than a planing hull. A planning hull driven at semi-displacement speeds will be less efficient than one at planning speeds. More than half of my offshore trips the boat can't be run faster than 16 knots because of the seas. (but that is on 25-30ft center consoles)

 

[firecat1981]

With that length to beam ratio and high gunnels, wouldn't it be very unstable in anything but calm conditions? It would certainly be very prone to wind, especially with the pilot house. And with only a 50hp motor you wouldn't be able to out run many storms.
Not to be a downer, but I think there's a reason we don't see many like this around here.

 

[Flatsaholic]

Build it. I would be interested to see how that works with a 50hp outboard. All I know is I would be super seasick on that boat lol.

 

[fpjeepy]

With that length to beam ratio and high gunnels, wouldn't it be very unstable in anything but calm conditions? It would certainly be very prone to wind, especially with the pilot house. And with only a 50hp motor you wouldn't be able to out run many storms.
Not to be a downer, but I think there's a reason we don't see many like this around here.

Yes and no. It would definitely be less stable. But what is the threshold of too unstable? I've paddled 20+ miles across the Delaware Bay on a 14ft x 23" paddleboard.

“If you never miss a plane, you’re spending too much time at the airport.” -George Stigler. In the same sense, if you've never flipped your boat, you could have gone narrower. I don't know anyone that has. I know it happens, but it's not so common that I can conclude 8'6" is the threshold for minimum stability.

Below is a commonly used boat in South America... Do you not see them because they don't work up here, or because we can afford more comfort?

 

[firecat1981]

In the same sense, if you've never flipped your boat, you could have gone narrower.

I can't even begin to quantify this thought process, and it's why we have safety standards in this country.
At 60" of beam you are talking maybe a 44-48" chine width max, meaning any wave taken broadside over a few feet puts it in danger without a huge counter balance which defeats the purpose.
But hey, I say do it! Pump a few hundred grand into setting up operations, then see what happens.

 

[Sublime]

I have no experience on the Atlantic. But here on the Texas gulf coast we often have stacked, unorganized waves with very short periods. It will beat the snot out of you. Hence, I wouldn't be a fan of relatively flat and narrow boats here. Swells with long intervals yes, here no.

 

[fjmaverick]

I've seen some Tolman skiffs do that but it will beat you up on rough days. They are really efficient too.

 

[LowHydrogen]

Stern needs to be much higher, imo.

People in the N. Atlantic (notoriously nasty) fished small boats forever.

If it were me I would get away from that style boat all together and go with a proven self bailing Dory design modify to be more efficient and build it light. Preferably something with a motor well for the outboard. They have been making those boats the same way for centuries, it's a proven and safe design, will haul an exponentially large load compared to others, and still get you back to the dock.

 

[ifsteve]

50 miles offshore. Narrow boat. 50hp motor. Not in a million years would I do that. Seriously thats just a disaster waiting to happen. For the very few days when the weather would be flat perfect you could just charter and come out ahead.

 

[fpjeepy]

I can't even begin to quantify this thought process, and it's why we have safety standards in this country.
At 60" of beam you are talking maybe a 44-48" chine width max, meaning any wave taken broadside over a few feet puts it in danger without a huge counter balance which defeats the purpose.
But hey, I say do it! Pump a few hundred grand into setting up operations, then see what happens.

Why does it put it in danger? So if the beam was 50% more and the waves were 50% larger would that boat be in danger? Cause I've taken boats with an 8ft beam in 5-7ft seas. Was it fun, not really. Was I in danger, I didn't think so.

I'm not talking about pumping $100K into anything. I got a quote for an aluminum build around $10k. +$2k for a used motor to try it out.

I have no experience on the Atlantic. But here on the Texas gulf coast we often have stacked, unorganized waves with very short periods. It will beat the snot out of you. Hence, I wouldn't be a fan of relatively flat and narrow boats here. Swells with long intervals yes, here no.

IMHO narrow boats are better than wide boats in chop, if you are talking about pounding.

 

[Sublime]

IMHO narrow boats are better than wide boats in chop, if you are talking about pounding.

Narrow isn't the problem, but flat bottom is and I don't see much of a vee? And if you put a deep vee on a long, narrow hull that requires a lot of power if you want planing.

 

[ifsteve]

Because you can do something doesn't mean you should.

 

[Cut Runner]

I really appreciate your out of box (if you've never left the 48) thinking as I do the same.
The problem is there is no "free lunch" offshore, unless your in a sail boat.
The closest thing to your model is a mexican 25ft panga. And there are quite a few with them that do far offshore trips. Granted they usually have 115hp at that size. I've explored the same ideas and ended up just finding an old 233formula and have been rebuilding that. I put a hull extension bracket on and a single 250 4 stroke putting it in the 3mpg average range. Not bad for a 25 foot boat that is super capable. I also built a similar pilot house which aids in the captain's and occupants comfort greatly, overall making the boat extremely capable and efficient for its size

 

[eightwt]

I think there is a reason that offshore boats have dual power many times.

 

[fpjeepy]

Narrow isn't the problem, but flat bottom is and I don't see much of a vee? And if you put a deep vee on a long, narrow hull that requires a lot of power if you want planing.

Narrow hulls require less power. And at 16 knots for 30ft is below planing. FnL≈ 0.9 ideal hull form would be double chine semi-displacement.

 

[firecat1981]

Your talking about taking it 50 miles offshore. If you don't understand the dangers involved there with such a narrow beam on a lightweight hull in open Atlantic waters then I doubt anything we point out will actually make an impact.
Good luck, I'd also be wary of the material specs on that 10k for the hull, no way is that for proper thickness and support.
Narrow can move efficiently with less power, up to a point. You are still going to be pushing a lot of weight and friction at semi displacement.

I get what your after, and we've all fished crazy ways in small boats at times. However if your looking to turn this into a business here, look at the market. How many panga companies have gone out of business? And that is a proven design.

 

[fpjeepy]

Your talking about taking it 50 miles offshore. If you don't understand the dangers involved there with such a narrow beam on a lightweight hull in open Atlantic waters then I doubt anything we point out will actually make an impact.

I ran a charter business out of new england for 4 years and first-mated on a number of boats for an additional 10. I have plenty of experience 100+ miles offshore. But I don't understand, so please enlighten me.

Good luck, I'd also be wary of the material specs on that 10k for the hull, no way is that for proper thickness and support.

0.16" 5083 plate. What would you recommend?

Narrow can move efficiently with less power, up to a point. You are still going to be pushing a lot of weight and friction at semi displacement.

At what point does it change?

I get what your after, and we've all fished crazy ways in small boats at times. However if your looking to turn this into a business here, look at the market. How many panga companies have gone out of business? And that is a proven design.

Not really looking turning it into a business. More just for myself. But well-founded criticism can point out errors in a design that could save me some bills later. I have lots of ideas. Many of them have issues. I enjoy the criticism.