What is the Absolute Lightest Propulsion Available?

[Chotu]

Up to my usual kooky stuff here. Thought experiments, basically.

Imagine you wanted to get ashore, but they don’t allow you to leave your regular dinghy overnight.

You need to get ashore 2 miles away and get back later too, but you can’t leave a trace ashore or it’ll be confiscated or stolen. You must bring it all with you.

A lightweight, roll up raft could work if it was light enough. But how would you get it moved the 4 mile round trip?

A tiny outboard seems like it’ll work. What’s the lightest one made? Or is there another type of propulsion that would work?

I’d say rowing, but the lightweight roll up raft won’t row properly.

Electric? The battery weighs a ton, right?

How would you do this, given you also bring the stuff that got you ashore with you? Assume you also can bring a little dolly ashore to wheel the stuff around but you must minimize the weight on the dolly.

How would you do it?

Note: I have a RIB with a 9.9 tohatsu. This is a secondary way of getting ashore in other “leave no trace” situations

[chrisr]

inflatable kayak ? they paddle quite nicely...

cheers,

[rslifkin]

Inflatable kayak is probably the best option. Basically you'll want something that rows or paddles well and can be carried by a single person. A small Portabote with a tiny engine would work, but if you don't need to take much stuff along, I think the kayak wins.

[StuM]

Another vote for inflatable kayak!

[Bruce K]

I have a TAS Tanaka outboard, weighs 5kg with integral tank.

[Rumpi]

It all depends on who you are. If you have reasonable expectations to finish an ironman competition tomorrow, you can buy an inflatable paddleboard and a 3 piece carbon paddle. Total package weight with pump and bag should be 20-25lbs. If not ironman material, buy a 7-8ft airfloor dinghy, a 2.5HP outboard and an Al trolley/sack cart with decent sized inflatable wheels. Total package weight is 70-90lbs depending on what boat you actually choose.
The lightest outboards still in production are the Suzuki BF 2.5, the similar but aircooled Honda, Selva Guppy, and the 2stroke Tohatsu 2.5 and 3.5. All come in at ~30lbs.

[Don C L]

I have a large inflatable kayak, 14 ft, large tubes, pretty tough, meant for white water. I could fairly easily carry that as a back pack for 4 flattish miles (Total weight a little under 50lbs pump and paddles inc.) Once inflated it is very rigid, especially the drop-stitch floor, so it paddles pretty fast, even into headwind. For your situation though I'd get the 12', plenty of room for 2 people or yourself and lots of groceries.
https://www.cruisersforum.com/forums...ture28931.html

[seandepagnier]

bring an umbrella to help sail half the time

[thomm225]

Folding kayak. Mine is 16’6” weighs about 40 lbs and fits in a backpack. Folbot Cooper.

13’ Feathercraft Foldable is 31 lbs and fits in a backpack also.

[Alan Mighty]

Calm water? Or wind waves?

Considered an inflatable SUP - a stand up paddle board?

Lighter than an inflatable kayak.

https://www.outsidepursuits.com/best...-paddle-board/

[Macdoug]

Oru folding kayak. Expensive but folds up neatly and can be carried with you. I chatted to someone who was paddling one and he said it was great. Not tried it myself.

[Franziska]

Originally Posted by Macdoug

Oru folding kayak. Expensive but folds up neatly and can be carried with you. I chatted to someone who was paddling one and he said it was great. Not tried it myself.

I've also seen those live. Great solution to the OP's problem/thoughts.
Very nice, but true, it's costly.

[Chotu]

Ok, some great responses! Thank you. I wasn’t aware how lightweight those kayaks were.

What about those weed eater engines?

As you know, I’m probably up to something crazy and didn’t want to cloud the responses with all the details just yet. I didn’t want everyone to think “that’s impossible” or “what a dumb idea.”

But now I’ll tell a little more. The item in question needs to also carry a nearly 300lbs load to shore and back. As much as the inflatable kayaks are perfect, are they a bit too much the same as regular kayaks? Do they roll very easily?

The big reveal here is that for personal reasons which I’ve publicly wrestled with on this forum, I need transportation that I bring with me on the boat. After 30 years on boats, most of that living at anchor, I feel trapped by them. I enjoy the peace and quiet, the nature and wildlife. But I want to go inland too, on a whim. I want to be able to go see people and live a more normal life on a boat. My girlfriend is taking some time to work through some things in her life, so I’m solo on the boat most of the time. I need my own transportation to go 100 miles inland at the drop of a hat.. Why? Uber prices are getting out of hand and it doesn’t exist in remote areas which I’m much more interested in traveling to these days. Bicycles and non street legal things don’t go far enough or fast enough.

I had designed this whole very cool detachable walkway for the bow of the catamaran that you could lower to the water and raise up. The walkway is the piece you see in the middle in the following pic between the 2 sections of netting. It had inflatable tubes on the sides and would be towed as a motorcycle trailer ashore for the “leave no trace” approach. However, that piece is kind of short on my boat. So it doesn’t work. Motorcycle doesn’t fit.



So it was back to the drawing board. I’m tired of the drawing board and putting time and money in. So instead I wanted to try to approach the problem from the motorcycle camper or backpacking side, not the boating side.

Their approach is to make things simple, lightweight and minimal.

Lo and behold, plenty of people have moved their motorcycles across the water to resume a ride on the other side and did it with items they carried on the bike on a long camping/expedition trip.

Examples:

https://www.youtube.com/watch?v=YyM4LqcVV2Y

https://www.advpulse.com/adv-rides/r...ukotka-russia/


Now, being a boater, I know those solutions are more suited to wading across rivers and lakes than a choppy anchorage with a headwind.

The larger beam on the rafts makes a stable platform for transport, however.

I especially like the first YouTube video above where you lash the bike and raft together and tip them over into the water. But it still needs propulsion in a real life situation against wind and current in an anchorage. Rafts row /paddle less than poorly.

Two schools of thought

1). You could do exactly as the above pictures and videos and towthat setup ashore with the regular dinghy. That means an extra trip.
a. Load bike onto raft and put it in the water
B. Launch normal RIB and tow bike setup to shore
C. tip bike back upright at shore and remove raft
D. Tow raft back to mothership, put real dinghy back on davits, stow raft
E. Paddle an inflatable kayak back ashore
F. Deflate kayak and pack away onto motorcycle
E. (Reverse are steps above to get back to the boat)

Or....

2) Ride yourself with the bike in the raft and use the lightest form of propulsion available. Those steps would be:

A. Load bike onto raft and put it in the water
B. Grab handheld lightweight propulsion device
C. Attach device to raft
D. Bring all ashore in one trip
E. Tip bike upright and deflate raft
F. Stow raft AND propulsion device on bike and go
G. (Reverse the above to get back on the boat)

Advantage for the first school of thought is much lighter weight setup and way better motorcycle trip. Disadvantage is you have to make multiple trips which would suck for going to get a bolt or nut at a hardware store 10 miles away only to find you need another one when you drop it overboard by mistake.

Now, yes 300lbs is a fair bit of extra weight on a performance cat. I have some living space sacrifices I’m going to make to account for this. Also I’m a light guy myself and some boat owners are 250 lbs anyway. So it’s not as much as you’d think given I’ll drop 300lbs in luxuries elsewhere on the boat to make up for it.

Getting it on and off the boat is tricky singlehanded.

I was thinking I’d have a couple lifting rings welded to the frame of the bike on the side. That way, I can lash the raft on while on deck and pick it up in a horizontal position to lift off the boat and lower into the water with the raft touching the water first and the whole thing in the correct position as it meets the water. I’m thinking a custom gin pole attached to the mast will do the trick nicely using a halyard. I’d use the boom, but it won’t put the bike on the foredeck which is where I need to store it. Too risky trying to wheel it or walk it anywhere on deck on a moving boat. It should drop right on its storage spot.



Now with the reveal done, the thread is open to more creative ideas.

The reason everything needs to be as lightweight as possible is I’ll pack it all on the motorcycle to travel away from the boat overnight.

And dinghies are not allowed to be left overnight in 90% of locations. So “leave no trace” ashore is very important.

[rslifkin]

I think the 2 trips ashore option might be best. You already have a RIB capable of carrying enough. And I'd expect in m most places that you'd be taking the motorcycle ashore, your distance to shore would be fairly short. And the more compact the final shore transport is, the more other stuff you have room to bring on the bike.

How big is the RIB you already have?

[Chotu]

Originally Posted by rslifkin

I think the 2 trips ashore option might be best. You already have a RIB capable of carrying enough. And I'd expect in m most places that you'd be taking the motorcycle ashore, your distance to shore would be fairly short. And the more compact the final shore transport is, the more other stuff you have room to bring on the bike.

How big is the RIB you already have?

Yeah. Much better for the motorcycle riding to not have to carry a water propulsion system. Although with a really crappy 2hp outboard, I could probably just chain it to a tree or hide it and chain it, leaving it behind until I return.

I think it’s a 9ft RIB. Maybe 10ft. I kept it small and light. The 9.9 is way too much power for it.