Ultra efficient boats

[freebeard]

Think ecomodding a small boat presents new challenges that could be a lot of fun.

I like the idea of a diving platform that has a notch in it to dock a jet-ski. It would be used as a tugboat for the raft, or as a tender.

The notch at the front of a catamaran raft. Filleting at the sides of the jetski to make the combination an M-hull.


https://external-content.duckduckgo.com/iu/?....&ipo=images

[new_bug]

I didn't dig in to the whole thread , only the first few and last few pages- but take a serious look at russell brown's of pt watercraft (wa usa) highly developed solution to this exact question. tornado (beach catamaran type) hulls with 20hp efi outboard, and lightweight pod.
https://www.offcenterharbor.com/vide...t-motor-boats/


those interested could find more info via a dedicated google search.


The propulsion (outboard motor) could still be optimized, electric? propane? (perhaps), diesel ? at least diesel ..ought to do better efficiency than a gas burner.

The takeaway; long waterline (hull length to beam/width ratio) , multihull, extreme low weight

[freebeard]

View at 40 per page and it's still page 2.

Looks hard to turn.

Tech Ingredients did a series on catamarans.

The Tesla Catamaran!

We Went Back In Time To Make Our Boat Go Faster...

Taking the Tesla Boat out on the water!

[redpoint5]

I'm always perplexed as to why boats have abrupt sterns, but pointy bows. Fluid dynamics apply in water as it does in air, so you'd think that is where the taper should be located.

The fishing boat we chartered last weekend got 2 MPG with 2x 200HP Yamaha outboards at 25-30 knots.

Got my limit of 2 halibut.

... I wonder, if you're already paying for shore power, is it metered? A boat with ~100 mile EV range and emergency outboard gasser would be pretty ideal. We covered about 45 miles on our trip.

[freebeard]

A boat with ~100 mile EV range...

Cars have it easy. The road doesn't flow for and against them.

I watched the Back In Time video. Turns out they retro-fitted a Thai long-tail motor. What no-one ever mentions is that the reason the setup became popular in Thailand in the 1970s is you can stick the prop shaft down a tube and have an irrigation pump for the rice paddies.

[new_bug]

Yes, the funky pod catamaran is certainly not optimized for easiest docking, (it's optimized for efficiency with 15-20hp gas outboard, and crossing open/exposed water at relativity higher speed). Other than than close quarters docking which can be a "challenge" on lots of other more normal boats, I'm sure handling would be fine.

Especially in the next size up 20-30ft, a single outrigger (maybe double outrigger too?) type boat is also a great option.

Just look at the basic- "large canoe shape boat" with or without outrigger/s that's found in various forms. historically with and without sails.

This general "cargo canoe" shape, 20+ft, type boat/ category-with upto say 40-50hp sized outboard is hard or impossible to beat as a compromise on general utility/efficiency on big rivers worldwide and traditional reef fishing etc.

[freebeard]

If the outriggers capture the bow wake of the center hull that's pretty close to the M-hull at Permalink #51. It has a flat connecting plate that captures a bubble of air (really froth) underneath to make it a partial-lift ekranoplan.

[cRiPpLe_rOoStEr]

Originally Posted by freebeard

What no-one ever mentions is that the reason the setup became popular in Thailand in the 1970s is you can stick the prop shaft down a tube and have an irrigation pump for the rice paddies.

Similar setups, but with smaller engines, have also been quite usual in Amazon as it was easier to avoid damage to the tail while navigating through a shallow waterway with some tree roots underneath.