Since the last time I sat down to write an installment of this column, I’ve several times put myself in a spot to interact with the tide.

On the day of the lowest winter tide I went out at night to the mudflats to help gather eel-grass samples. In the middle of a Sunday afternoon, I waited with a friend on the bluff above Useless Bay until the tide was out far enough for us to walk south from her house and around the point toward Maxwelton Beach.

In Coupeville, on two consecutive Wednesdays, I noted that though I arrived at the same time each day, the tide was out the first day and high the second and was surprised at the dramatic difference just a week made. Driving to work along Shoreview Avenue on a very high tide day, I could have sworn the water lapping against the grassy berm was higher than the road. This where-is-sea-level optical illusion is something I’ve wrestled with before. Do my eyes deceive me? There’s no better place to check than at Deception Pass.

Just after Christmas, I had to go to Oak Harbor on an errand. Whenever I go that far north, I try to first drive past the city and spend a little time at Deception Pass watching the eight-knot ebb- tide surge through the cut in the shape of whirlpools, eddies, standing waves and smooth, upwelling humps.

My favorite place to watch the tide and currents is on the eastern tip of Pass Island in the center of Deception Pass, so that’s where I headed.

First, I meandered down through the forested north side of the island that runs along narrow Canoe Pass and marveled at the turquoise water so unexpected of the gray Northwest. Then I crossed over and hiked down the south-facing slope to the trails that trace the rocky shore.

That tip of the island juts out into the pass like the prow of a ship — complete with a bow wave along the southern side. I always hunker down there as low as possible, trying to sight along the surface to see if I can tell what’s going on with the water.

There’s a curious phenomenon there — I’ve watched it for years. The water to the east of Pass Island is one level, and then it falls away to the south at least 12 inches.

I always thought I was nuts, or my eyes were playing tricks on me, but I’ve read that sea level is not the same everywhere, so I went back again to take another look.

Sure enough, there is a distinct difference between the sea level on one side of Pass Island and the other. Right at the bow wave the water cascades into a hole. Later I called Ranger Rick Blank at the state park to see if he would verify what my eyes were telling me. He did. The way he explains it, there’s a sort of stair step effect with the water rushing out of Saratoga Passage, building up as it gets restricted at the narrow mouth. Once the water pushes past the island and into the center of the channel, it can move faster and flattens out again.

Trying to get definitive proof of what I was seeing, I filled my camera’s memory card over and over, going back through, deleting pictures I thought I could live without. When I couldn’t delete anymore, camera completely full and still unsure whether anything I’d captured would answer my questions, I began the hike back up the island. As soon as my back was turned, I heard a splash behind me. I stopped and looked back, hoping the fish would jump again.

My patience was rewarded a minute later. Except it wasn’t a fish, it was a sea lion. I waited again, watching the spot where he’d surfaced before and sure enough, again he jumped up that cascade like a salmon up a ladder, then disappeared beneath the surface, letting himself be taken back by the rushing current.

I couldn’t take video because my card was too full to run between the animal’s appearances, so I quickly dumped a couple more stills and aimed the camera. Over and over he jumped, 10 or 20 times; I lost count. I got several nice shots of his antics and then of his subsequent ride on the currents and whirlpools as, presumably worn out from his play on my bow wave, or Ranger Rick Blank’s stair steps, he let the current carry him down the pass toward the bridge.

For more information: Sound Waters — A one-day university about Puget Sound, click here.

Deception Pass Bridge turns 75 on July 31. Call Deception Pass State Park at 360-675-3767 to get involved in the birthday celebration.

For more info go to my Tidal Life Blog.

Questions or comments for Tidal Life? E-mail tidallife@whidbey.com.