I installed a Spirit Line seat in my SOF kayak yesterday. It’s an SC-1 built (by me) at Cape Falcon. The seat covers the rib that was putting my legs to sleep in excruciating fashion, and which normal foam pads weren’t taking care of. As a bonus, the connected hip braces plug me in to the boat much better than before.
I had to put some deep slots (dados) in the underside of the seat to get it to fit down into the frame. I left a little space between the seat and the skin to let water move around. For now, it’s stuck in with 3M indoor/outdoor mounting tape. If that fails, I’ll move on to something stronger. The slots keep the seat from moving once you’re weight is on it, so the tape just keeps it from popping out otherwise.
I haven’t paddled it more than a few minutes since the install, but it feels much, much, much better. Here’s a photo series of the fairly easy installation:
http://s97.photobucket.com/albums/l234/carldelo/SC-1%20mods/
Seat looks nice
Good install too.
Curious about your backband though - seem like it’s there mostly to pad the coaming rim - and I’m wondering why you didn’t place it lower and attach to the gunwales so it could sit more on your hips, pivot with you, and be adjusted for aft to keep you a bit forward of the coaming if desired?
SOF seating
That seat does look comfortable, as long as it does not raise your COG too much. Another option is to cut out the offending rib (make it a half rib). This is usually not necessary as it is customary in a Greenland kayak to space the ribs in the cockpit so that you sit between ribs.
Greg Stamer
Fine Job
Much nicer than I would have done.
I have installed two of these seats into hardshell kayaks - and they ROCK! However, the last one I did I found that NDK makes one the same as this except that its covered with material much like your backband. I believe its better to sit on contact-wise and also will wear MUCH better. Might cost you some $$$$ though, but its worth it!
As to your seat back - I echo Greyak’s question about positioning it lower and slightly forward to keep you off that rear coaming more - it will make layback rolls better and may end up trimming your yak out more efficiently too. This of course is dependent upon whether you installed a foot brace, and if so, if it allows you to move forward about two inches from the rear coaming.
Once again - super installation job! I will look you up next time I do any outfitting! 
Scott
Forgot to ask!
What brand backband is that and where did you get it?
Thanks
Scott
Back band info
Thanks for the thumbs up - I have to say it was a pretty easy installation. The backband was provided by Brian during the construction. It’s a Snapdragon Back Band #1, which Rutabaga carries:
http://www.rutabaga.com/product_images.asp?pid=1000625
You-all are right that in the early pictures, the backband is just about touching the coaming. I moved it back to try to get my butt off the rib. I never considered cutting out a rib (yikes). In later pictures in the sequence, you can see I’ve moved it forward so there’s a couple of inches behind it now that rib placement isn’t an issue.
The attachment to the coaming is Brian’s design - I hadn’t thought about moving it lower. It doesn’t sit so high though - it tends to rotate down inside the cockpit a little and rest at the small of my back. Clearly it doesn’t inhibit Brian rolling the boat - here he is in full layback before I moved the band forward (I don’t have a roll yet):
http://s97.photobucket.com/albums/l234/carldelo/Accord%20NY/?action=view¤t=Accord012.jpg
Re: center of gravity - with seat slotted, my CoG feels the same as with a layer of waffle paddling over the frame. I’d say at it’s thinnest spot, there is about a quarter inch of foam seat over the top of the rib. The thigh braces are a major bonus, too.
I wish I’d known about the NDK seat - where would you get one of those? I may put a fabric cover over the current seat. If you look at the pictures close, you can see a lot of nicks in the foam - if you order from Pygmy, ask them to wrap the seat so the other stuff in the box doesn’t chew it up. I should have sent it back, but I wanted to install it right away. CLC sells the seats too. I considered a Bumfortable seat, but would have trouble hacking up a seat that cost $140.
On a side note, why does minicell foam cost so much? Is it just because they’re selling to a niche market?
Cheers, Carl
NDK seat
Hi
Just contact any retailer that sells NDK boats for this foam seat. West Coast I would go to Jen at Aqua Adventures - East Coast then it would be to Tom Bergh at Maine Island Kayak Company. (MIKCO)
Not sure, but think it sells for about $65 and based on my use of it in my Black Pearl, its a jewel! (pun intended)
BTW - Brian could roll a darned cruise ship!
Scott
That’s where
Brian drilled the holes on my Ginnyak. I have been having the same problem, (keel wedgie) the seat looks like a good fix.
How do you
put up with the keel wedgie when you sit between the ribs? You also get butt deformation of the skin, don’t think it slows you down though 
Next time
Next time I get ‘keel-wedgie’ (love that), I’ll get the upgraded seat. I bet Atlantic Kayak Tours up the Hudson could get one. I’ve heard from Brian that this seat installation is going to be included in future SC-1 classes, so I guess I got it right the first time.
Brian
Yes, Brian only uses what works for his non-replica boats so that is high praise for you. If I am not mistaken, he is now doing a building class for this design up in Sitka Alaska this week. Funny - I would have thought those folks up there would be more interested in the 1935 Greenland replica design there paddling the inland passage.
Scott
Surfing
Maybe they want the SC-1 so they can surf the wakes of the cruise ships going by. Or they want a wider boat so they don’t have to worry about capsizing a skinny little Greenland boat in that chilly water (kidding, sort-of)
Foam Pad and "spruce wedgie"
A very common method, in Greenland and elsewhere, is to ensure that the edges are taken off the stringers and ribs in the cockpit area.
You then place a thin foam pad that reaches from your heels and up to the deckbeam at your back. The pad makes it easier to enter/exit the kayak (your heels don’t catch on ribs). The pad also adds comfort (including padding the backrest deck beam) and insulation and keeps sand and grit from getting into the lashings (which is very destructive to a SOF). After use you remove the pad to remove the sand and grit and to allow the kayak to dry.
Sitting directly on a pad on floor in this way keeps your COG very low. If your ribs are spaced properly this can be extremely comfortable (and it eliminates the “spruce wedgie”).
Greg Stamer
Update
After a couple of years, the Spirit Line seat that I installed in my SC-1 has progressed into being more and more of a torture device. I assume this is tied to my advancing years and general decline in fitness level. I tried modifying the top of the seat to make it work, but no joy. Whatever - yesterday I tested it and after 35 minutes my legs were fully asleep to the extent that I capsized while getting out of the boat onto dead legs.
But the real point was that I was there to test the Gurney Gears Bumfortable seat I bought to replace it. I put it in with no adhesive or notches for the ribs, and was able to paddle for 90 minutes without numbness. The seat’s a little thicker, so I was higher in the boat. Not a problem as the boat is stable, plus I was able to rotate easier into the bargain. In fact, after the paddle, my back felt looser than when I started which I’m pretty sure has never happened to me before.
Anyway, next time out I’ll notch it to fit down over the one rib it sits on, and take out the Snapdragon backband that’s in the boat now. The Bumfortable has an integral backrest which was comfortable, flexy and probably has enough support on its own. Apparently, when you lay back, the sides of the seat compress into your hips slightly, locking you into the boat a little more firmly. One last benefit - the backrest is just high enough that it holds the spray skirt deck up behind my back, preventing the pooling I usually get back there. So I guess I’ve drunk the Kool-Aid on this seat, but it’s almost like having a new boat - it’s much easier to focus on your technique when you aren’t in pain (well, duh).
Cheers, Carl