Answering my own question post cruising on the Ascent. Yes, the seafood buffet is the last day at sea, at lunch. It was very good with chilled shrimp, crawdads, fried calamari and tempura seafood, three kinds of ceviche (cod, shrimp, scallops), beautiful red snapper and other fish, mussels. The ceviches were not the best I've had, more like a seafood salad, but very acceptable. It is a bit of a zoo, with the chilled station line up starting half hour pre buffet opening. I found the station with crawdads and chilled shrimp settled down quickly though, so you might want to start with the cooked sea food, it had almost no line up to start with. savor it and then move on to the chilled station. It's also chocolate fondue day, and that line up is slow because staff serve you (which is fine by me, it could be a real mess otherwise). I didn't see any hording really, maybe I just didn't notice it. I actually found many people were pretty selective about what they would eat.