Check out this picture of USS Philadelphia (SSN 690) after a recent mooring in Groton:
Notice all the white stuff on the sail? That's ice. I remember quite a few very cold surface transits in the Long Island Sound, but nothing where I saw this much ice. There was this one, though, when I was a NUB on USS Topeka back in early '91, where I was manning #1 periscope on the surface during an outbound transit (as Contact Coordinator U/I, if I recall correctly), and every couple of minutes a wave would hit the optics of the raised 'scope -- followed a couple of seconds later by a huge slug of water coming down the bridge trunk and hitting the bear trap. Someone suggested we shut the lower bridge hatch to keep everything from getting wet, when someone else remembered a story of a boat that did that, and then had the bridge trunk fill with water and then something clogged the drain valve, trapping the OOD and lookout on the bridge. We ended up moving the OOD below and navigating the rest of the way out to the dive point at night, with reduced visibility, and no one on the bridge. I wonder how that would be looked at in today's ORM-centric environment...