tiggymalvern | Lake Washington I-90 sunken bridge dive

Lake Washington is fairly narrow, but it also gets very deep, so it's crossed by two bridges which descend to float on the surface of the water - one of these is the I-90 bridge. In 1990, while the bridge was closed for resurfacing and widening, some poor engineering decisions were made and many sections of the bridge sank. The piece at the westernmost end lies in shallow enough water for easy recreational diving.

The current I-90 bridge still floats in the middle, and of course it's directly over the sunken portion, so even on a beautiful sunny day, the bridge dive is a night dive - there's no daylight making it under there. You can feel the vibrations of the big trucks through the water while you're underneath the current bridge. Besides the intact section of bridge, there's a lot of other debris down there - from big stuff like girders, to general detritus like traffic cones and hubcaps. Some of the fish make use of it all for hidey holes.

We followed the line of reflective poles down to the sunken section of bridge, swam along the outside of it, then swam back in over what used to be the roadway and sidewalk/pavement. When you get back to the daylight in shallow water, there's a lot of weed.

I would have got much better video if I'd remembered to take my camera in December, when I first did this dive. The water last week was soupy with plankton, visibility only about 10 feet, as opposed to 25 feet or so in December. On the other hand, I was chilly when I got out of the water in December and perfectly toasty last week, so you pick your poison!

I confess the shot of my dive buddy in his car at the end is cheating a little - that was taken on a different day when we dived Three Tree Point and my camera stopped working after just one underwater shot.

I can't embed the video here, because youtube want you to watch it there so they can advertise on it, so here's the link. HD highly recommended!