Time and Tides; Sucia Island State Park; Echo Bay; Ship Wrecks

We’ve been through several tide cycles while sailing in the San Juans. There are times when the tide swing is large and steep, resulting in some serious tidal flows in any narrow passage between islands. If you have a large boat with a little engine you watch for the big flows, and then avoid them. Time it wrong and t’s possible to be ‘full ahead’ while actually moving backwards. As captain I plan our routes through passes at high or low tide, and then fudge it just a little so if delayed, the flow will help us get through, giving a little push in the right direction.
Today our route took us from the south side of Orcas Island all the way around to the north side and then a bit further to the Boundary Islands. These are the last American Islands here. A little further north and it’s all Canada. This was the longest distance we have traveled in a day and it took us through Obstruction Pass out into Rosario Strait and then north through the largest open waters we have yet seen. The tides were gentle and in our favor, our passage was calm and without incident. We did encounter some swells generated far south, possibly from Juan de Fuca Straight. They were big, slow rolling things that Odyssey had no problems with.
Clearing Lawrence Point we angled northwest and headed straight for Sucia Island, ten plus miles off, visible on the overcast horizon. The spaces here are great, open water as far as you can see, then islands or towering mountains in the distance. Almost two hours later we came into Echo Bay, Sucia Island, our stop for the day. Having read this was a busy place during the summer, we weren’t surprised to find about a dozen boats there. It’s a big bay with lots of State Park mooring balls. We found one quickly and ‘picked’ it up. This involves passing a line through a steel loop on top of the buoy. This way we don’t have to drop our anchor.
The wind died down and the clouds departed leaving a warm sun and near mirror waters. I did have my doubts about this spot. When we anchor in a new location I’ll leave the instruments on so I can verify location and depth for a safety. So there I am, sitting at the helm watching things, and the depth meter goes from 22 feet down to six in just a few seconds as we drift in the light wind. As I stood up it went right back to 23 and held. What? Something wrong with the gauge? I watched for awhile and sure enough there it went, shallow again. I dashed up to the deck, peering into the clear green water to see what was below us. I’m thinking there must be a wreck down there, I doubt the park system would install a buoy with rocks right below it. After 20 minutes of doing this dance I caught a glimpse of the culprit. An enormous school of herring passing below the keel. So dense in numbers my depth gauge could read it. With a grin and sigh I stood down from watch. 
Tomorrow we explore the island. Unlike the rocky geography further south, this area is dominated by sandstone, known for being sculpted by wind and waves. It should be beautiful.