Originally Posted by K_V_B
The problem is that in reality lasers aren't that visible. It's not like in the movies... You normally don't see the beams, and only a dot wherever it hits.
They (the guys in the link) use lasers you can meet in laser levels. These lasers draw a line, not a dot, and it is a line you see on the wall (this thing is all about laser marks on surfaces, not in air). I can guarantee it is perfectly visible, I have a laser level and it works like a charm painting beautiful long red line on the wall even in a daytime. At night, you will see nice red lines going back and forth on the walls of you pilothouse and on the deck
. Impossible to not see it, and very impressive unless you know what it is.