I agree with Greg, when I row chafing is only a problem on the erg! That seat shape chafes me raw under the tailbone. But once it has happened, you are a goner till it heals, as you point out Meatloaf.
On long rows on the water, I use a sore-no-more (sorbothane) seat pad, although sometimes row without it or with a wooden bead pad (like a cabbie), or both, to mix it up - change is important sometimes. I wear synthetic boxer briefs so they dry while wearing. I use now defunct Hydropel lube, but am told Aquaphor is acceptable - although 25% of the time I forget anyway, with no issues to date. And I have Gold Bond handy at night, and always a fresh set of underwear when I go to sleep.
I find it important in rowing to sit up on your sit bones, not slouching on the back of your a$$, so your torso can rock/pivot back and forth without doing damage.
If you are not rowing a sliding seat, I'm not sure how much of this applies. For the lifeguard races I think they go bare cheeks and soap! LeatherLungs might have insight if you are rowing a dory or such.