The Aluminum Unicorn

[bajansailor]

Can’t afford gas outboards, and definitely not diesel. I also can’t stand the look of an outboard. If I’m going to put all this effort into building a boat, I better love every part of it. And diesel is a must.

What is your realistic budget for this build?

 

[comfisherman]

A wide-beam, semi-planing aluminum workboat hull adapted with modern underwater lines should be quite practical in Puget Sound, especially for weekend range and shoulder-season use. Expect the design to live more comfortably in the 18–22 knot semi-planing range rather than true high-speed planing, particularly with an inboard diesel like the Cummins 5.9 and crane loads. Starting from a proven PNW seine skiff or utility hull and redesigning only the topsides and weight distribution is likely your safest and most cost-effective path.

Does this look like a text book large language model summation of the op thread? Ive built and operated a pile of "proven seine skifs" not a single one would be a suitable topside redesign.



At any rate. I dont know who did the laconner maritime initial design. They were jig built, on a configurable jig. Was more thinking of a design that someone familiar with bay boats from the prop generation of boats would be able to identify. That's slew of 13.5 to 15 wide bay boats is pretty close to the same length to beam ratio as a 10-10.5 foot wide 24 footer. Without gear and fish they ran in the low 20s

Recon cummins is gonna hit 30, second hands still gonna be upper teens, what's marine plate going for 5-6$ ? a pound in smaller volume. Gonna hit 30-40k with wastage and extrusions pretty easy. Windows, doors, hardware never mind steering gear shifting electronics and driveline. Priced a zf that's a twin of the one I bought in 21'... between tariffs and inflation it was just about double. A gear is now a non trivial purchase... then you still have plumbing and the bits and bots that add up quick like high pressure oil coolers and engine soft mounts.

Assuming you own a decent pulse mig and a shop to work in and the other 10k in hand tools that will aide in a faster build.... 140-150k seems low but doable.

 

[Bakodiver]

Bertram 25 has a 10 foot beam, just sayin. I've seen a lot of photo spreads where DIY guys modernize and repower this hull, they seem to come out very nice. Not an aluminum boat but there are a lot of advantages is using a well proven, capable hull that is available cheap. Edit to add that I don't know a lot about US EPA laws, but if you do a new build don't you have to have a common rail diesel to meet tier 3 or 4 requirements? If you rebuild an old hull you can still put a mechanical engine in, so far as I know.

 

[BlueBell]

the perfect boat to add to my collection

but it really fits my needs perfectly.

Sounds "perfect".

So why hesitate? You can't beat "perfect".

The fact that I think you're wrong isn't going to change your mind.
Probably best if you stop typing and start building.
Please post lots of pictures of your final design and build.
I look forward to seeing your progress.

What's the proposed completion date and budget?

 

[Milton best]

i will be doing everything myself from start to finish, so completion date is certainly up in the air. if i could build the hull and cabin for around 40K, id be happy. I have some connections in the aluminum industry that might knock the price of material down a good bit. as for the odds and ends, i have a 40' container full of parts to choose from, so i should be able to do everything but the engine and hull for pretty cheap, likely another 10k.

the thought has crossed my mind that an existing hull would weed out some paperwork issues, but i havent found an acceptable one yet. if there were an aluminum bertram, i would strongly consider it to save a ton of time, but no such luck. but it is a fair point, does a new "homemade" hull need to meet 25 emissions specs? that will likely result in a far more expensive powerplant. i just cant help but love the old 5.9. open to other more modern equipment as well though.

modern under water, classic above describes exactly what im after. scaling down a bristol bay boat would be a great path forward in my opinion. the real reason for me starting this thread is to try to track down plans for a hull that fits my needs. im happy to scrap the cabin design on a good set of plans and come up with my own if needed. i am interested in finding an existing hull design that is proven so that i dont waste my time building a boat that ultimately doesnt comply with what im after - planming is the biggest concern. im hoping to start the build in august. i have 90% of the tools that will be required, so no need to worry there.

 

[DogCavalry]

Meet Serenity. 33 knots with a ton of cargo on board. 26'x10', shallow draft, ultimate stability, fast in bad weather. Cabin 9½'x13' Power is a 250 outboard. Better with a pair of 115's

 

[gonzo]

If you rebuild an old hull you can still put a mechanical engine in, so far as I know.

If you repower with a new engine package, it has to be EPA compliant regardless of fuel type. However, you can buy a complete long block (no valve covers, brackets, accessories, etc.) and it can be a rebuilt or refurbished old style mechanical injection.

 

[gonzo]

does a new "homemade" hull need to meet 25 emissions specs?

You can rebuild an old aluminum boat. For example, save a few original pieces and build the rest new.

 

[Milton best]

I thought about that too. Save the HIN on the transom and build around it. Kind of like “remodeling” a house by leaving just 1 wall

 

[william stokes]

Greetings boat design gurus.

I have dreamed up the idea for the perfect boat to add to my collection. The problem is, from what I can tell, it does not exist! This of course only means one thing, time to build it…but first, I want to see if anyone on this forum has any knowledge of a design like this.

Let me walk you through what I’m after.

I am located in the Puget Sound, and I love sailing and cruising on the trawler. The issue is that I am simply mortal and must work to afford such great luxuries. This means that I am typically stuck with choosing between only a handful of destinations for a weekend sail/cruise. This boat is my solution to that. Fast, functional, sleep on-able, durable.

I would like to keep this boat relatively small - 24ft max so that I can trailer it. I am planning on building it out of aluminum. I like the low maintenance aspect of aluminum and I plan to use this boat as an adventure rig, so durability is a must. It must be able to plane, preferably with a top speed in excess of 20 knots. I know that speed seems low, but that is because I want it to be an inboard diesel. I am thinking v-drive might be best because I am pursuing a classic tug design that is going to put the bulk of the super structure towards the bow. Direct drive would be ideal however.

I have worked on fishing boats in Alaska for years, and being regulated at 32’ in Bristol bay, designers have gotten creative and started building wiiiiiide boats. 32 feet long x 18 feet wide in some cases.

I would like to do something similar with this boat. I am thinking 10-10.5 feet wide will make up some nice extra space on such a short boat. I also want the extra width to add stability, because I intend to put a mast and crane on the boat to allow me to load my DR650 motorcycle on the back deck - no more being limited to areas local to the marina/anchorage. Finally I plan to have a low cabin behind the wheelhouse, just enough room for a mattress and to be able to sit up on it, and the head in the bow. In my mind, this is the ultimate adventure rig for 2.

So, now for the gurus. I would love to design the whole boat myself, but I am not so proud to think that my design would be better than one that’s already been proven. So, I am looking for a hull design that would meet my criteria. I fully intend to design the superstructure myself.

approx 24ft in length
approx 10ft wide
Planing
Aluminum
Classic styling, vertical bow shape, not sloped forward
Open to stern drive, but would prefer inboard because I can only imagine the cost of diesel stern drive parts…

is anyone familiar with a hull design like this? The closest that I can find are seine skiff designs, but the styling is wrong.

Also, please chime in on the practicality of this design. I know it’s going to be very unique, but it really fits my needs perfectly. I am thinking 5.9 Cummins for a power plant.

get in touch, have what you want and all dwgs free

 

[comfisherman]

A friend had one of the last batches of mavrik prop drive boats. I think they were the fastest prop boats built for the boat, or at least the fastest traditional aluminum boats. Think it was an in house design adaption of the kvichak. Friend had his built to finish out his career and as far as prop hulls it really scooted along.