I've had a few uncomfortable moments because of the lack of vision. One time we were sailing at night, just ghosting along when I hear some chatter in Spanish right in front of our boat! I don't know what they were saying but they were excited. On this occasion, my son was with me and he didn't see anything either. When passing by, I noted that there were no lights on their small runabout (they were just drifting in the middle of the lake and they seemed to be picking themselves off the floor of the boat for some reason ...).
Another time, we were on starboard tack, but sailing along at about 3 knots in a light breeze on a busy Sunday morning. We were near the upwind mark for the LHYC fleet but the fleet was well behind us so we had no concerns, thinking that we would be well past the mark by the time the fleet got there. So about 50 feet off our port bow, hidden from view, I hear a loudspeaker cautioning me that I am on a collision course with the race committee pontoon boat! I have no idea when they got there but it was embarrassing for sure! Luckily for me, our dog Shelby went to the port side to make some new friends (she doesn't have enough sense to be embarrassed ... imagine!) and she did a great job of smoothing over the entire episode.
A few weeks ago, my wife and I are booming along on a starboard tack, me at the helm and Sue with her eyes closed enjoying the sunshine. A tiny little trimaran, made for one person to sit in one position while puttering around with a single mainsheet for sail control and a cooler strapped to the mast, passed my bow about 20 feet in front of me (on a port reach). I was pretty startled but he just seemed to casually tip his drink as he went by. I never saw him coming as he must have been behind the genny the entire time.
I've had a few uncomfortable moments on port tack myself ... I want to have my clew cut higher so I can see under. It's a busy lake and it doesn't take much to lose sight anybody on the other side of the sail.