I have been fishing on the North jetty on the columbia looking north towards north head and saw as many as three in the air at once. The first time My dad and I saw it was about ten years ago, and we could not figure out why "sharks" were jumping. Then one came up right in front of us with its back toward us and there was no mistaking the white diamonds down each side. I have had a lot of people look at me like i'm crazy when I talk about that. Have never found out why they do it...and it only seems to happen at the same time every year...