Expedition Pedal boat design

[Peddler]

Hi there, I am trying design and build an expedition pedal boat. I think the maximum length for navigating rivers in the uk is 5m.
I am hoping to achieve 5-6mph from 150w pedal power. Ideally I would like to be able to cruise for 5-8 hours. I think total weight of myself and gear will be under 100kg. Id like to have the fastest possible boat within my remit.


I am unsure as to the best hull design for my purposes. The fastest pedal boats are long trimarans, but I feel that this might not be the best for travelling down rivers.

Catamarans are great for stability but I’m not sure if they create unnecessary drag.

Kayaks that have enough stability for recumbent pedalling tend to be slow fishing kayaks. Maybe a kayak with outriggers might be good but I’m not sure if speed will be compromised by a kayak hull.


What do you guys think? Very interested in any ideas you have

[Clarkey]

Will be an interesting thread. What is your reference for thinking 'the maximum length for navigating rivers in the UK is 5m'?

There are other practical considerations such as getting on and off the boat at the bankside (which happens an awful lot when river cruising) - low volume outriggers put you away from the bank and won't support your weight when you step on them - might favour a catamaran?

[Peddler]

I’m calling it at 5m mostly because I used a sea kayak that was 6 m and total pain to manoeuvre. I’m happy to be corrected on the matter. Also any more than 5m is going to be hard for me to transport.

outriggers can be hinged. You can deploy them when necessary, and also raise them.

[Edward Pearson]

If you want to explore while using your legs for propulsion, i’d reconsider the Hobie’s. Easy to live with, transport and well designed they are not slow (as quick as a kayak) and easy aquistion and resale. Plus storage, recumbancy and sail options. If it must be home built, the CLC Wanderlust sailing canoe has a hobie drive. The mirage drive parts will be £500-£1000 though.

I’d also wonder what the rush was. If you’re making the effort to drive to a beautifull river, i think a simple 17ft strip canoe, a dry bag of gear and a paddle would give you a peacefull simple afternoon and you’ll not miss the flora and fauna. Easy to move and transport.

There’s really only the Wye valley of any length, i think travelling with a paddle most of it is done over a long weekend. Getting back to the car is the biggest logistical issue, people fo it for you on the wye but other rivers are going to require a driver. Travelling twice as fast but seeing half as much might be the reality head down at 4-8 knots.

There was a chap called Dads Boats who built pedal powered boats and built his own props. I think he’s closed it, but he’d be worth talking to and will give accurate speed expectations. I think he wanted to sell his boat molds too...might even be able to sell you a boat.

[Edward Pearson]

https://m.youtube.com/watch?v=lCXVQfrmBX8

Pedal boat review (the one above).

[rgthom]

Might as well start with a proven pedal boat design, Gartside #92 "Blue Skies": https://store.gartsideboats.com/coll...kies-design-92



This is bigger than your brief, at 6 m and 115 kg, but it shows a sleek monohull has worked and covered many thousand miles. Blue Skies has an enclosed sleeping cabin. That is not in the brief so I assume sleeping will be ashore, is that right? Gartside reports sustainable speed of 4 kts, so maybe a lighter version with narrower beam could do better.

The drivetrain is worth studying. It uses a straight shaft from a gearbox so the prop is slightly angled, a u-joint in the shaft allows prop and skeg to kick up when beaching.

[rgthom]

Not to talk you out of this, but just give my view: I am a cyclist and rower, with an expedition type camp aboard rowboat. I've thought about trying to do a pedal drive, but decided against for the following reasons - Oars are an efficient and robust method of propulsion, keep it simple. Pedal drives add complexity and failure points. Slide seat rowing uses the leg muscles developed by cycling. My back is weak from an injury, but I can slide row and it helps to strengthen it. A propeller in the water limits the depth you can travel in, and is susceptible to catching weeds and other debris.

I recently added an electric outboard to my boat, on the local waters the prop snags on something several times each outing and must be raised and cleared. For a pedal boat it would be important to be able to access the prop while in the boat in case this happens. An alternate method of propulsion should be available, in case the drive stops due to clogs or failure. For a monohull, a double blade kayak paddle could be at hand and would help in close maneuvering.

The Hobie drive as mentioned by Edward seems more robust than a propeller, still more complex than oars but they are well proven.

Again not trying to say don't do it, just some issues to manage. A pedal drive has the big advantage of seeing forward while underway.

-Rick

[Todd Bradshaw]

We are in our second year with the Hobie 180 Mirage drives (kick-up fins with forward and reverse) and after almost 60 years of canoes, kayaks and other small boats, paddles and oars just don't seem to make much sense any more. Propellers also seem to be pretty poor options on small boats. The thing about nearly all Hobie stuff is that it is really pricey (or just plain overpriced) but it generally works beautifully.

I also think your desired cruising speed is unrealistic, unless you're in a big hurry to get home. Our Hobie Lynx hulls are not particularly sleek (11' x 36") but we an cruise at 3.5 to 4 mph. which is a nice speed for seeing the scenery. On a sleeker hull you could probably pick up another knot or two without feeling like you are working hard. You do need a couple feet of water under you and it is possible to catch some weeds, though they are easy to clear by quickly raising the drive and rudder and sending it back down. We can pedal through big patches of dense lilypads and then clear the drives and rudders in about ten seconds without even needing to leave the seat.

[keith66]

There is a long running thread on pedal boats over on the Boat design forums, hundreds of pages long. Every possible permutation has been tried.
If you limit it to 5m it will be fat & slow, basically a pedalo.
If you want a pedal boat to be fast it has to be long & thin & lightweight to have any efficiency.
The best layout has proven to be a skinny monohull with triamaran style outriggers, right angle gearbox driving a trailing propellor.
Rick willoughby in Australia has built a series of ever more efficient pedal boats & has videos on you tube.

[wdr99]

. You do need a couple feet of water under you and it is possible to catch some weeds, though they are easy to clear by quickly raising the drive and rudder and sending it back down. We can pedal through big patches of dense lilypads and then clear the drives and rudders in about ten seconds without even needing to leave the seat.

I’ll also vouch for the Hobie mirage drives. We have their kayaks and their tandem sailing trimarans and they are fantastic. I’d note that you can pedal through very shallow water with quick short pedaling strokes which keeps the fins close to the hull. Very versatile craft.

Bill

[Woxbox]

I understand from your earlier thread, Peddler, that tinkering and building the drive unit would be the fun part of this project for you. Given that and the 5M length, your best bet will be a skinny canoe-type hull to house a recumbent drive mechanism. The lighter and skinnier the hull, the more speed you'll be able to squeeze out of it. You could put together such a hull pretty quickly with tortured plywood covered with fiberglass. (Search user flo-mo's threads here for samples.) Your height, weight and familiarity with light narrow boats will determine how narrow a boat to go with. I'd start the study at somewhere around 28". You could take it down to 20" or so if you were to add an outrigger, but I agree with Todd that 5-6 mph would be unlikely other than for a short sprint.

A 16' canoe from flo-mo.

[Talentless]

I like the idea of a pedal boat, I am also in the UK, it would be ideal for the canals, probably not so much fun in the locks, so it would have to be portable and be able to be carried on land rather than go through the locks.

I saw a design that was quite unique, a link to the video is below

https://i.imgur.com/bHNpnaZ.gifv

[Geftb]

I saw a design that was quite unique, a link to the video is below

https://i.imgur.com/bHNpnaZ.gifv

that’s awesome!

[Jack Loudon]

that’s awesome!

I second that! Ingenious in its simplicity. I also appreciated Todd's comments from last week about Mirage Drives vs oars and paddles. As a long time bicyclist and some time oar & paddler, I appreciate how much more can be done with leg muscles, plus your arms are left free to do other things.

[Todd Bradshaw]

Yes, that is very clever, and also seems to be pretty efficient. I think he should try to fit a shirt and a hat on the mechanism at the stern.

As for speed..... some days you simply don't want to go too fast and miss the experience.

hobie-Brown-Lake.jpg

[Jack Loudon]

I have a concern about pedal or Mirage Drive kayaks, and that is stability in rough water. Most Hobie and other pedal kayaks have wider hulls than true kayaks but still on the narrow side, and exacerbating this is their high seat which would raise the CG. I couldn't imagine using a kayak in rough water without the bracing effect of the paddle. Todd's beautiful photo shows the pedal kayak in benign conditions but I'd like to know do they do in open water, like Puget Sound?

[Todd Bradshaw]

First of all, there are a variety of different Hobie hulls that use Mirage Drives and some might be better rough water hulls than others. In our case, we are using the Mirage Lynx hulls, which are basically similar to a paddle board (11' x 36"). They are extremely stable as well as unsinkable/unswampable. I wouldn't have any problem taking my Lynx anywhere that I'd take my sea kayak.



Regardless of your desire (or not) to ever own one, if you ever get a chance to demo a Hobie Lynx, take it. They are really amazing little boats and will spoil you quickly.

[Jack Loudon]

Thanks Todd; very encouraging.

[MattMKE]

I found one of these http://www.clcboats.com/shop/boats/p...ing-canoe.html with the Hobie Mirage drive on YouTube and it looked slick.

[Talentless]

The guy who built the pedal powered oar canoe has his build on Youtube

here are the links

Canoe Build https://www.youtube.com/watch?v=eH7Z2kkHomc

Pedal Power https://www.youtube.com/watch?v=m8Z1CYuscno

First test. https://www.youtube.com/watch?v=1PEMc88WsUs&t=115s

[Dryfeet]

Another vote/accolade for the Hobie Lynx! We love ours. No, it's not wood. Yes, they are pricey, ok, expensive, but they're very light weight, require no maintenance other than rinsing and very fun for a couple hours out on the water. Todd, get the Hobie Bimini accessory, it's a game changer in the summer sun. Yes, Hobie IS quite proud of it, but the sun protection is worth every penny (says one who is funding his dermatologist's retirement plan)

There will be a minimum of 2, maybe 4 on the mothership. They also stack quite nicely.

[Todd Bradshaw]

Yes, we have the Bimini tops, and they are a wonderful addition. We have found that they can make the boat a bit squirrelly once you get up much above ten to twelve knots of wind, but they can be taken down and stowed pretty quickly while underway out on the water. Like other Hobie accessories, they are really pricey, but extremely well designed and effective. When we're up north at our place on the lakes in the summer, life is generally one day on the water and one day on the trails, all in pretty much the same position. Our arms may fall off due to lack of use, but at 70 years old, I can live with that.

Being a guy who once built a big fur trade canoe, just to see what it felt like to paddle one (it feels like just about any canoe, only heavier) if I was younger, I'd probably be figuring out how to strip up a long, needle-shaped hull just to see how fast the Mirage Drive could make it go. At this age though, I'm quite satisfied with the stock version.

Screenshotts.jpg

For those wondering about the Lynx, there is a pretty good demo video here. Yes, it is 100% wood-free (foam core, fiberglass wrapped and a plastic outer shell) but it's a blast to use.

https://www.youtube.com/watch?v=BdRUlzVxZmI&t=215s

[Dryfeet]

Yup, waterline is everything and the Lynx doesn't have a long one! In fact, my 5 year old grandson can peddle the 14' Hobie Oasis tandem faster than I can pedal the Lynx--with his 230# Dad riding along in the tandem but not pedaling. The Mirage drive has pretty good speed potential by itself in any case.

(End Hobie advertisement here )