Yes, but when nuggets get dumped in the ocean, what's underneath the placer will make all the difference as to whether the nuggets can be recovered. If there's a deep and very soft sediment deposit they're hitting, they'll work their way down quickly, and I know that's an issue in lakes as well.
Up north in a remote placer goldfield, there was a great little creek that produced nice nuggets, and there were huge boulders all along the creek which impeded recovery of those nuggets for the early placer miners, and with today's mining laws, it's still not possible to work the stream to remove the boulders either, even though modern-day equipment would easily do the job. The gold was coarse right up to where the stream discharged it into the lake, but it's a very deep glacial lake, and it's too deep to dive (in the mountains as well, high altitude, which seriously complicates the dive tables), where the gold got dropped off the shelf, plus the bottom is muck.
So, yes, it's possible under the proper conditions, with a suitable underlying clay or bedrock bottom that's not too deep (water not too deep as well) so the nuggets will hit and stick. If you've watched Bering Sea gold, and I've chased the gold along the Bering sea, clay layers will stop the gold from dropping, as of course would any bedrock shelving. There were some guys dredging there off the mouth of a stream where I was working that were getting some good stuff from off some clay that also held a lot of rocks.
All the best,
Lanny
