Sliding seat for cruising rowboats

Sliding seats are a big problem for cruising boats, because they take up all the middle of the boat and get in the way when you want to for camp, cook or just laze around. Worse than a centreboard.
Rick Thompson in the San Francisco Bay area has built one of the most interesting rowing/sailing boat designs around, John Welsford's Walkabout. Now he has added an ingenious sliding seat mechanism that runs on the side flotation tanks, leaving the centre well free for other purposes, such as sleep. Rick describes it in the very excellent John Welsford forum thus:

I'm pretty happy with it so far. I know JW is not so keen on sliding seats, and I understand that it probably burns more energy and doesn't do anything to change the hull speed limit on this type of boat.

For me, it is a big help to be able to use leg muscles as well as arms and back. Next will be some type of hold-down so the seat can be used fixed as well.
It's really hot here in inland California now, hope others are having good
boating or building weather.
Rick

I have to say I rather agree with John Welsford about sliding seats on long-distance boats. When you are racing over relatively short distances, you need to transmit all the power you can possibly generate into the oars. It is a sprint, so it's anaerobic.
Over longer distances, it is physically impossible to row anaerobically - the power you can produce is limited by the amount of air you can pump through your lungs. And you can produce this power just as efficiently on a fixed thwart as a sliding seat.
If you use a fixed seat, you get the other advantages of better control over the oars in choppy conditions and a more robust and simpler setup. But with the sliding seat, Rick will be able to make a lot of money by challenging fixed seat Walkabout owners to a race to "that buoy and back". Go, Rick!

A Walkabout for rowing

John Welsford's Walkabout is a boat for cruising, under oars and sail. It has a very appealing combination of length for easy rowing and a man-size flat area on the bottom for comfortable sleeping.
This blog's favourite expat Brummie Rick Thompson noticed that it has a lot of excellent features for a pure rowing boat that is used in more challenging waters, in his case San Francisco Bay. The decks and coaming keep out all but the worst waves, and there is lots of flotation should the worst occur.
So Rick is building a Walkabout for rowing, stretched by eight per cent to 17ft 10in and without all the sailing stuff. A few days ago he had a trial launch to fix the rowlock positions. She was blessed with a splash of Guinness and named 'Puddles' - and she looks very good.
Rick wrote in the Welsford forum:

"The boat I have been rowing for the past 4 years is a 14' Whitehall type, known
as a decent pulling boat, so my comparisons are to that. Steady long distance rowing speed for the Whitehall has been 3 - 3.5 kts, and Walkabout measures about the same on GPS. This is great, I was afraid the bigger boat would be slower. Pulling very hard, Walkabout got to 4.5 - 5 kts, faster than the smaller boat probably due to longer waterline. Even at this speed there is very little wake generated, where the Whitehall would be surging and making waves.
The Whitehall is sensitive to fore and aft trim, and more tippy. With two people in Walkabout, not trimmed properly as there is only one rowing position at the moment, it made very little difference in speed. I can also sit out on one side seat and the rail is still well above the water."

The result is much more seaworthy and practical cruising boat than the Whitehall. Rick has lots of pictures of the launch and the construction process here.