I live in Massachusetts and started following these these two cases when they were still disappearances, and I've always thought they really might be connected to the "river killer" cases. There's no real rational explanation for how these two young men ended up where they did - one in the Charles River, the other in the Boston Harbor. The man who was discovered in the Boston Harbor years later was staying at a hotel with his girlfriend and went outside for a smoke in the early morning hours after a late night out in the city.
and here were some threads on his disappearance and recovery:
Also, William Hurley, who disappeared after a Bruins game in Boston just 4 months before Gene Losik, and was waiting for a ride home from his girlfriend:
Both men were in the middle of doing normal mundane things - going outside for a smoke, waiting for a ride home from a hockey game - when they disappeared. They'd each had alcohol that night but neither appeared impaired to people that were with them. IMO there is no rational explanation for how they ended up in the water - no way they could have accidentally fallen in - Hurley disappeared in October, when the nights in Boston start getting cold, and Losik in February, when it would have been undoubtedly frigid at that hour.