Maybe I should have posted the whole joke.

“I was in the first submarine. Instead of a periscope, they had a kaleidoscope. “We’re surrounded.””

— Steven Wright

Ok, how about…

The first submarines didn’t have a periscope. They just had a porthole in the front so you could see if you were going to hit anything. It was called the collide-o-scope.

I don’t get it