This is partly a continuation of this question, since that one was already closed, but my question is about a specific problem encountered the last time I cooked scallops.  I got the pan up to a reasonable temperature and put the scallops in, and as they were cooking, TONS of water came out of the scallops and filled the pan.  I poured it out, continued cooking, and more water came out.  Several iterations later, I thought they were done, but they were still very raw inside, so we ended up tossing the batch (it definitely wasn't sushi grade).  Where did all the liquid come from, and is there any way to avoid that the next time? 
I've had this issue with crappy supermarket scallops before. Alton Brown covered this. From http://www.goodeatsfanpage.com/Season9/scallops/scallop_trans.htm (section 5):     dry scallops are usually ivory, or   slightly pink, or even orange in   color, not white. Of course, they   don't actually look dry. The term   refers to the fact that these lovely   lozenges have not been soaked in any   kind of chemical, say, sodium   tripolyphosphate. This solution is   used to help scallops retain moisture   when frozen. Now there's nothing wrong   with that per se, unless the scallop   in question is not going to be frozen.   You see, treating fresh scallops with   S.T.P. causes them to gain moisture,   making them heavier, which could be a   good thing for a retailer, but it's   never good for a cook. Because once   this stuff is inside the scallop, they   become very difficult to cook   properly, and they are impossible to   sear properly.   Diver scallops are probably good. Look for a bit of color when buying. The good news is that you probably aren't doing anything wrong, the scallops just aren't going to sear.  When you buy for searing, get scallops that haven't been treated with chemicals. Diver scallops are almost always untreated. Look for a bit of color, which is usually a sign of quality. Don't buy them if they are in a pool of milky liquid (as they usually are in the fish section of the supermarket). Buying diver scallops is also much more sustainable and eco-friendly, since large ships that freeze their stock at sea dredge the floor to get scallops. Divers are much more selective and do negligible damage to the ocean floor. 