It only took 10+ years, but I finally took Makai to a beach! It was the first REALLY nice day of the year, so I took him to Discovery Park.
My original plan was just to prepare him for hiking season and see how he'd handle other dogs on the trail (verdict: poor). However, I had forgotten that you can hike all the way down to the beach, which is something I'd always wanted to do with him, so we wandered down to the end of the trail, right past all the "NO DOGS ALLOWED ON SEATTLE BEACHES" signs. (Well, whatever. I had poo bags and a leash and there were other dogs having fun down there.)
We lucked out and got there right at low tide, the sand went out forever. All the ripples made it look like water. Gorgeous!
I was worried he'd be scared (he totally avoids puddles and sprinklers and hates the bath) but the old boy clomped straight into the water like it was no one's business. He was a little timid, and wouldn't let me wander too far away, but I think he had fun checking it out.
Also at the beach, I think I found the world's teeniest muscle. :)