Two sliding seat rowing positions in Sea Pearlgreenspun.com : LUSENET : Open-water rowing : One Thread
I have a 21', 600 lb open cat ketch with leeboards called a Sea Pearl. It's like a whale boat. We often sleep in the boat (It has a collapsilbe cabin.) The original rowing arrangement is for one fixed seat position amidships. It came with 9'6" oars.
Any thoughts on modifying it for two rowing positions? It's hard to row much faster than 2 miles an hour for very long and our tide current is 2-3 knots here on the Georgia Coast.
Any thoughts on two sliding seats that could be tucked away so we could still camp on the boat?
-- Dan Lockwood (email@example.com), November 29, 2003
The sliding seat method was developed for use in flatwater shells. Those boats are very long, extremely light, low-sided and narrow. The farther your boat deviates from that description the less efficient sliding seats will be in your boat. Your boat has pretty sleek lines for a sailing craft, but it's larger and heavier than even most coastal workboats which typically don't benefit from the sliding seat method at all. A sailing craft is optimized for sailing, which means it's interior is somewhat busier than most rowing craft. Adding all that sliding seat apparatus will render the interior of your sailing craft nearly uninhabitable. The idea of two fixed seat rowing stations in a boat as big as yours doesn't seem like a bad idea, but you'll be amazed at how even two pairs of moderate length oars add to the clutter on your boat. Nothing is going to turn a 600 lbs. hull into a high-performance rowing craft. If you're looking for a truly rewarding rowing experience perhaps you should consider getting a dedicated rowing craft. For the price of two rigs with matching sculls you could purhase or build a pretty decent rowing craft.
-- Andre de Bardelaben (firstname.lastname@example.org), November 30, 2003.
I agree with Andre about having two sets of oars inside your sail boat. They will always be in the way, that's without the seats! Even if you get some sort of collars that allow you to break the oars down into seperate pieces.
But to attempt to answer your question: The simplest sliding seat I've seen is a bench with two sets of roller blade wheels on each side. One set is mounted vertically and one set horizontally so that when the seat is on a track, i.e. a dropped L shape track, the vertical wheels ride the inside of the "L" and the horizontal ones are just below it. Takes 8 wheels per seat and the seat tracks must be parallel. The nice thing is you can drill a pin hole in the track and drop a pin through the seat and into the track to hold the whole seat in place (two pins, one on either side.) Then the seat is a plain old fixed seat. And no more in the way than any other seat in a sail boat. Gig Harbor boats use this technique.
When you don't want the seats, you can pick the units up off the track and stow them in the bilge along with 4 oars, etc and kick the mess everytime you tack....
Now this arrangement isn't going to make your boat particularlly fast to row. Its still heavy to row 600lbs. But you will get your legs to help so you should last at least 2 hrs before having to rest depending on your conditioning.
While this is a "rowing" forum, I'm going to suggest one more heritical idea and that is you could get an electric fishing motor. If you want it totally out of the way you can buy a unit from Gig Harbor that mounts on your rudder, or get a motor mount and just hang it off the stern. Get a out board motor extension and use that to steer it. The battery is heavy but its useful for camping for having some lights, running a radio etc.
-- Gary Powell (email@example.com), November 30, 2003.
Dan, After having looked over the Sea Pearl web site I have a couple of more comments.
The first is adding a second rower, even with a fixed seat, will help move the boat faster and/or easier.
Second, you'll need two more positions to row, one forward of a midships, and the second aft so the two rowers will balance the boat boat.
Third, adding extra oar locks if you have the open cockpit design boat shouldn't be too hard. Adding the seats may be a lot more work depending on how skilled with fiberglass you are. Of course with some nice bronze seat holders ( "L" brackets ) and some teak or mahagony seats would work for a permanete seats. But then they'll be in the way for sleeping. So some sort of rail and seat that drops on top with a pin to hold them in place should work. These pins are sold at marine supply stores and have a ball at the bottom to lock it in place and a button on the top to press to release the ball and unlock it. Just put a strip of metal on the seat rack and drill a hole into it to make the seat lock in place. You'll want to do this for sailing so that the seats don't move when you heel.
Fourth, and I probably don't need to mention it, is to install some sort of backing plates to spread the load around the fiberglass where the oarlocks are mounted.
Anyway its a nice looking sailboat. -Gary-
-- Gary Powell (firstname.lastname@example.org), December 01, 2003.
No rowing rig in a Sea Pearl is going to overcome a 2-3 knot current, or a stiff headwind for that matter. Dare I say it? Some circumstances require a motor -- or patience to wait for more favorable conditions. A motor mount is available for the Sea Pearl, for those who flirt with heresy.
-- Kim Apel (email@example.com), December 01, 2003.
Re: beating a 2-3 knot current.
So the low end hull speed formula should be 1.2 x sqrt(21) or 5.4. Couldn't two rowers in good shape push this boat at 4 knots? Now admittly a 1 knot difference in over the bottom speed isn't great but it might get you home. I know that I've rowed my dory against the tide/current to get in and my theoretical top speed is only 4.4kts. It took awhile but I'm home. With a head wind, he can always sail in.
(For my money the outboard is the way to go.) -Gary-
-- Gary Powell (firstname.lastname@example.org), December 01, 2003.
Ive been rowing a 16' modified grand banks for four years and just dropped in a sliding seat this year; I picked up a used rowing machine at the local goodwill store for $15,removed the arms and after some experimentation ended up with an inclined rig set on wooden blocks that butted up against the motorwell of the dory. The incline position came about after forsaking the idea of strapping my feet into the sliding rig,due to safety factor involved in rough sea conditions; and my need to move around while fishing; the slight incline allows for easy return to the pull position after completing the stroke. The block system not only allows for easy removal (the sliding rig is not attached to the boat itself), but also eliminates the possibility of getting a foot jammed between the gig and gunwal(?) of the boat; ie the rig will be kicked aside before the leg is jammed;again this was important when maneuvering /standing up in the boat at night,in rough conditions: it also allows for quick removal of the rig itself,if needed (pulling anchor,hooking into "moby fish", or thinking your'e hooked int the big one. I did not shop around for used rowing machines; my initial sighting was perfect for the job; but you might keep your eyes peeled at yard sales,flea markets etc. The other option that worked was tying the seat to the midrails,again allowing for easy removal,but I opted against it finally for safety reasons; I don't know your boat, but encourage you to experiment before deciding; the cheap used rowing machine option might give you an idea of the increased performance you might expect. Thanks,good luck. Ed Norton
-- Ed Norton (email@example.com), December 01, 2003.
Thanks for the thoughtful and thought provoking replies. The discussion is a real contribution to Sea Pearl owners and I am going to file it in our discussion group. I'll be experimenting with your ideas over the next few months.
It really surprises me that the designer of the Sea Pearl only put in one rowing position. A boat of that size would go much better with two rowers, which would have been the traditional configuration.
I never thought of what Ed suggested, but I think I may be able to try it with a sort of rowing exercise machine that was left out by the street in my neighborhood as trash. It's called a Health Rider.
I'm also intrigued by the rowing systems in ocean rowing boats. They use sliding seats and also sleep in the boats. I'm amazed that Tori Murden rowed 50 miles a day in a boat heavier than mine, day-after- day.
Oh, about the motor. First, we like rowing. Second, I'm preparing for a 300 mile race in March where no motors are allowed.
-- Dan Lockwood (firstname.lastname@example.org), December 06, 2003.