I love sea glass and went hunting at Discovery Park in Seattle today. I didn't find much but did find something made out of ceramic I'm hoping someone can identify for me! It's almost 3" long, the top (at the widest) is almost 3/4" wide and the hole that goes through the length of it is just under 1/4" across. The break at the bottom is very worn. It has a very small stamp at the top which is a triangle with possibly a "v" inside it. The top is a little cockeyed when you look at it from the side, maybe from being in the water for so long and wearing down. I keep thinking it may have something to do with electric power but really don't have a clue. I'm hoping someone out there knows what it is! Thank you!
What you have there is a ceramic tube, part of the "Knob and Tube" electrical wiring insulators used in building houses back around 1920 or so. The "Knob" was also ceramic about 3/4 inch in diameter and 1-1/2 inches high. You still can find them on old wooden electric fence posts.
The part you have is the "Tube" and was used to insulate the wire when it was threaded through a joist or truss in the rafters or walls of the house.