Stand-up Paddleboard Design

FYI

what you are talking about is a "standamaran".

This guy talks about the dynamics

https://www.youtube.com/watch?v=d39NOFm_hMM

I question some of his assertions but he is sure making some nice craft.

It should probably have it's own thread.

 

Yep, the red one I posted above is the Standamaran, or "S-16," and I think it's the latest version. He mentions steering. I haven't thought about that. (hand to face)

 

^^ The guy on the red standamaran is an impressively muscular dude. That is likely to be the one of the main reasons that his boat is fast.

 

have you considered bigger distance between hulls and then paddling inside the hulls ?
That way you could have super narrow standing area suspended between hulls, a bit more distance between hulls to reduce wave interference.

just a thought

 

I have actually. I'm considering a totally new type of paddle as well.

 

The reason the cats are fast is not lower wetted surface area, other than the fact that guy on it would displace a lot less than me. Cat have higher wetted surface area, one hull is always more efficient that way. Where cats are good in pure displacement mode is wave formation, but that assumes you are really intent on driving the hull at the high end where that maters. In canoes, it has been shown over and over that low wetted surface area trumps low wave formation at the kinds of speeds most people who don't race are interested in.

Laird's design seems mostly to be a low wetted surface deal at the expense of stability design.

Stability is a situation where the cat has huge advantages, or potential. For that reason there are some interesting fishing inspired designs. Many of the paddle boards have a hollow in the middle, and while that increases wetted surface, it is a form of catamaran principle, pushing the displacement outboard.

It is not at all difficult to make a boat that is better than what is out there already on the first try. As you get down to this size of thing, it is like a pair of pants, custom fits a lot better than off the rack. And there is not just custom on the body size aspect, but also custom as to uses. This guy got his minute of fame, and that SUP design is about as crap as it comes, though customized for a specific use.



The double paddle idea is interesting. In NA, it took a long time to displace the canoeing heritage in favour of the Kayak one. Then along come these things, and it is all forgotten. I live a few hundred yards from a canoe club (indeed I got to this thread because I wanted to find the BD canoe forum), the guys go impressively fast in these stand up tubs that have terrible hydro, seems to be because they are able to use their legs a lot more. The average board is really stout, and would not be pleasant to paddle with a double paddle due to the low stroke rate. I was looking into a way of making the thing go faster, at about the same time I got a new kicker for the trimaran. I was thinking SUP because all the cool kids are there. The way the design evolved was to this:



Not normally a motor guy, but given I just bought one, it was pretty undeniable. I am making one in ply right now. It will SUP; pole; mirage drive; motor... Who know what else.

 

Hi there,

I realize this was an old post to inquire about. I'm curious to learn more about the rowing catamaran you made.

 

There use to be several threads with more info, but I forgot where.
Ask away and I will try to satisfy your interest.

What can I answer?

Marc

 

Hi Marc,

I stumbled across your post nosing around for rowing catamarans schemes. I have a Skimmer that I found several years ago and have used it a few times - it's limited to medium weight people and relatively calm conditions. I found some of your other posts/pictures of your setup on boatdesign. I was interested in seeing the detail on the sliding seat/rigger setup that you devised. How much does your cat weigh? Since we are in the middle of a pandemic and isolation I've had more time to circle back to past projects/ideas. I'm 74 and having health issues so there are limits to what I may be able to do once the dust settles on Covid-19, but the rowing cat has an appeal for getting more people out on the water and I'm exploring less costly ways of doing so than some of the commercial rigs.
Thanks, Al

 

Al,

The cat in the pictures is for my wife. She weighs 125# and it will not carry much more. It would be easy to scale up the hulls to carry a bigger weight.
The boat weighs 50# without the oars, but could probably be built lighter. The boat was sized to fit in the back of a full sized pickup - hanging out the end. It is 11' x 4', with hulls which are 6" wide (max).
It is actually easy to carry to the water because you can stand in the middle, right behind the front crossbeam, and pick it up by the two rails for the seat. Perfectly balanced and not too heavy, but cumbersome to turn.
The rigger and rails are relatively easy in concept. Getting the proportions right took 3 or 4 iterations so that the oars are in the water, your hands are at the right height, and your feet are not to high compared to your bum (and high enough to stay out of mild waves). Since I can give you the dimensions she needed, you can probably adapt easily to your size.
We use standard sculling oars. I thought they were 11' but the picture above they seem to be shorter - 9' perhaps. I can go measure if you need.
The rigger tubes or rails are 1" aluminum pipe (not tube) which are a heavier wall. They are bolted to the cross beams with a U shaped bracket made from a piece of square aluminum tubing.
All of this material is bought from the scrap bin at a local metals supply house. About $1.50/# depending on the day.
The two rigger tubes are about 24" apart.
The rigger is made of wood. The arm that holds the oar locks is pine (or cedar, I don't remember) joined in the middle with a spline joint and epoxy. Perhaps a bit of glass cloth top and bottom with epoxy.
The wheels are the worst part to find/ build/ source. Mine were machined from 1" plastic solid rod. The groove around the circumference needs to be 1" diameter but only about 3/8" deep. I also put metal bearings from skateboard wheels.
I am not sure those are really needed. It depends upon just how slick the plastic used is - you might be able to just put a bolt thru a drilled hole. The wheels and installation is the only thing that needs a little better precision on the whole boat.
I looked for a long time to find stock wheels - perhaps off of some exercise equipment. No one at the stores wanted to help.
When you build the rest for your feet, whatever you do, don't lace your feet in or use toe straps. My son tried to take a big hard stroke, didn't get the oars in the water, and fell off the seat backward with his toes hooked in. Luckily he was young and athletic enough to raise his head up out of the water by doing a situp.
If you put a heel cup on the foot board, that will be enough to pull the rigger back on the recovery.
The seat is a standard one for a scull. You might like something with a back to lean against while you are coasting or just admiring the view. Something out of a kayak would probably work.
The one thing that is not especially great is not being able to take your feet off the rigger. You have no place to rest them. It might not seem so bad if you have a seat back.

This is completely a one person boat.
Its not even good for fishing the way I built it.
But it rows easily and quickly.

If you needed a bigger hull I could estimate an appropriate size.
For myself at 225# I estimated 16' overall by 4' wide with 6" wide hulls. It might weigh 60#.
The hulls are made by strip planking covered with glass inside and out built on simple forms.
They are built similar to a strip planked kayak.

Could you give me a link to the older threads so I can see what pictures you have?
I'd be happy to talk about anything I've left out.

PS: I'm 68 and my wife 65 so I understand where you are coming from.
Did you get to see the video of my son-in-law rowing the boat?

 

Al,

I'm not sure I ever directly addressed what your question might have been.
Please let me know if you are still interested.

Marc

 

Marc,
Thanks for the reply and info. I got sidetracked by health/insurance issues lately which may keep me from doing any projects in the short term. I have not seen the video of your son-in-laws rowing the boat. The pictures of what you did I happened to find through “standup paddle board” posts I believe. I think I saw another pix of the boat stored on a rack suspended. I haven’t quite figured out how to navigate the boat design database yet.

I originally ran across catamaran sups on the web and thought adding a rowing platform might work. Also someone has come up with modular tubes that could work as a platform too. Fun to explore different ideas. I’m hoping to be able to pursue something in the future.

Cataboard sup, kayacat.com, standamaran are some other hull platforms I’ve found. Oarboard.com makes a rowing unit.
Thanks,
Al

 

Al,

I hope you surmount your health/ insurance issues. That sucks especially now.

I went looking on boatdesign.net and found some old articles.
Whatever I had put on woodenboat.com seem too old for their archives.

Unfortunately, I can't put files/ pictures/etc from my computer on this forum.
I'll try to send the rowing video (very short) to you on a PM. I'm afraid you have to have a minimum # of posts to get a PM.

So the following threads might have more info than the standup paddle board thread. Much of it will be a repeat, but you might have time to sit and read.

Catamaran like Rowboat for lake fishing https://www.boatdesign.net/threads/catamaran-like-rowboat-for-lake-fishing.47340/page-2
rowing rigs, forces of nature https://www.boatdesign.net/threads/rowing-rigs-forces-of-nature.49656/
sliding RIG, fixed seat, rowing setup https://www.boatdesign.net/threads/sliding-rig-fixed-seat-rowing-setup.49840/#post-679105
... the ROCAT story https://www.boatdesign.net/threads/the-rocat-story.50239/#post-685906
Stern Extension to Help Rowing https://www.boatdesign.net/threads/stern-extension-to-help-rowing.50924/page-2#post-696712
Sliding rigger rowing http://forum.woodenboat.com/showthread.php?180681-Sliding-rigger-rowing
rowing shell help needed https://www.boatdesign.net/threads/rowing-shell-help-needed.51254/#post-701862
Pontoon rowing scull? https://www.boatdesign.net/threads/pontoon-rowing-scull.60738/#post-835630

I like to talk even if you are not really ready to build.

Marc

PS: I can't send you a PM (or they just started calling it a "conversation") until you do a minimum # of Posts. Maybe 10. If you just make 7 answers to this thread that might work.
Just put some minimal message.

 

Marc,

Here's some other potential platforms I've run across. I have a competitive rowing background and know my way around rowing shells, but often wondered why more options weren't available for people to get into rowing without the steep learning curve of balancing a single 12" wide hull while learning how to scull. Not a big enough sustainable market out there. The Rocat looked pretty slick but then apparently couldn't afford to ramp up production. You may have seen some of these:
expandacraft.com Interesting modular approach - could get longer lengths as needed
kayacat.com inflatable system - lightweight - not available in the U.S.
SUP / Catamaran Hybrid | Paddling.com https://paddling.com/learn/sup-catamaran-hybrid/ 18' length would seem more favorable
The Most Stable and Easy To Ride Stand Up Paddle Board http://cataboard.com/
Shaboomee SUPS — Shaboomee SUP https://www.shaboomee.com/shaboomee-sup
WaterWalker 16 Glider (SUP) - Easy Rider Canoe & Kayak https://www.easyriderkayaks.com/waterwalker_16_Glider.htm
https://www.antidotepaddle.com/product-page/the-raptor-4x4-4-hull-quadrimaran
sliding rigger rowing system:
https://www.rowingrigs.com/product-page/sup-scull-rig

All this is on the back burner for now. Still getting kicked around currently with medical issues - feels like I'n a pinball in the system.

Al