Seat Pain, Feels like 2 Positions that "Switch" almost with a "Pop"

[MPx]

... especially as over the course of about a year, I adapted to it all and didn't need a seat pad at all.

I think there's definitely some hope at least in what Stu says here. I too used to suffer terribly from PITA when rowing. I believe much of my early dedication to short intervals was so that I could get up in between and relieve the pain. It gradually got so that I didn't need to get up between intervals and then slowly managed longer and longer sessions with no pain. (Not long in Stu's sense, but long for me - say up to 10k) I do still use my c2 pad on all sessions and on the very rare occasions I do an hour or HM then I sit on two pads stacked. It works at keeping the crippling pain away - but I think its more about slowly adapting to a lot of seat time (ca 50k/wk over many years) than making the seat comfy.

[Sakly]

... especially as over the course of about a year, I adapted to it all and didn't need a seat pad at all.

I think there's definitely some hope at least in what Stu says here. I too used to suffer terribly from PITA when rowing. I believe much of my early dedication to short intervals was so that I could get up in between and relieve the pain. It gradually got so that I didn't need to get up between intervals and then slowly managed longer and longer sessions with no pain. (Not long in Stu's sense, but long for me - say up to 10k) I do still use my c2 pad on all sessions and on the very rare occasions I do an hour or HM then I sit on two pads stacked. It works at keeping the crippling pain away - but I think its more about slowly adapting to a lot of seat time (ca 50k/wk over many years) than making the seat comfy.

Strangely enough I didn't need any time for adaptation. After two or three weeks on the erg I did my first HM and even on this I got no irritations at all (except blisters on my hands ).
Only shows how different we react to stimuli.

[iain]

I have always put PITA down to hardeniing glutes as they tire. Once hard the sit-bone movements dig into the muscles. This was at its worst on my 24hr tandem when the muscles hardened up during each rest. THe first few metres of each interval got progressively worse until I was starting at barely better than 3:00 pace when I was averaging 2:16. THe pain dulled fairly quickly to the "usual ache" of very long rows.

I have experienced something similar to OP (although more discomfort than pain, but the shift is very disconcerting as not the smooth stroke we aim for). I have experienced this in the last few years Just after I have lost the 5kg or so extra I put on when not rowing. Previously this has gone away in a few months of further rowing. I put this down to reduced padding and possibly a bit of wasting of my glutes from the inactivity. I noticed it for the first time Sunday after restarting in February.

[winniewinser]

I got the Citius Remex ProW today, low version, but I am not sure it has solved things better then the cheap seat just yet. I swapped back the stock seat, and with the pad it seemed much better at first, so much so that I possibly made the mistake of setting my feet from 1 back to 3 where I am more comfortable. At the end of a moderate session I was feeling PITA again, not as bad as with the stock seat, but possibly not as reduced as just the cheap seat with feet on 1.

I am hoping going back to higher feet will help, otherwise I might try to swap for the high version. I am skinny enough that I don't get the "on a bide saddle" feeling people talk about at all, even with the firm insert. I am also going to force myself to take a good break before I try again, as much as I want to just go back at it tomorrow.

I found making sure I get my sit bones firmly into the cutouts at the catch massively helped to alleviate the issues for me. When I set myself up "comfy" at the finish I was getting the pinching on the nerve - so might be worth experimenting with that as well perhaps?

This does seem to help at least initially, will play with it more!

I'm surprised the Citius Remex didn't help but I seem to remember it took a while for my behind to get used to sitting correctly. Maybe stick with it and see if over time it helps more.