Most tidal currents are the ocean sloshing back and forth. Deception Pass is a different animal: two large bodies of water sitting at different heights, connected by a gap a few hundred feet wide, with the flow driven by the difference in level rather than by the tide arriving directly. That distinction explains the standing waves, the noise, and the fact that the pass runs effectively one-way for most of every six hours with the direction alternating. It also explains why missing slack is a serious problem or no problem at all depending entirely on which way you were heading. Along the way: why the ebb consistently runs harder than the flood in the predictions, why no one can say for certain what causes that, and why the Skagit is not the answer even though it sounds like it ought to be.

Go look at: the pass at maximum ebb and again at slack, from the same spot on the bridge. Ninety minutes apart, same water.

A regulator picks the thing it can enforce, and the choice does not stop at enforcement. Washington chose yards. In the same few years it stood down the drone program that was scoring these whales' body condition, made a commercial reporting stream optional in the same bill that demanded an effectiveness report, and left standing a set of rules under which the location of an endangered orca is a controlled good, exempt from public disclosure and available in real time only to institutions. Meanwhile a voluntary ship slowdown a few miles south reports its results in decibels measured on hydrophones. Two programs, one water, and only one of them can tell you whether it worked.

Go look at: San Juan Island on any free vessel tracking site. There is a closure down the west side that motorized whale watch boats may not enter, year round, whales or no whales. See whether the fleet's tracks draw you the line.

Since January of 2025, every vessel in Washington waters has had to stay 1,000 yards from a Southern Resident killer whale. That is more than half a mile, it applies to kayaks and paddleboards, and the fine is $500. Federal law in the same water still says 200 yards. Canada, as of this June, says 1,000 metres. This episode asks where those numbers came from and finds that nobody ever solved for one. The oldest was chosen in 1995 because prosecutors found it a useful line, and the rest are copies, roundings, and a nautical unit that was already the working radius of the whole system before it was ever a rule. Then it finds the harder problem underneath: the rule turns on telling a Southern Resident from a Bigg's killer whale at half a mile, which the state's own advisory group calls very difficult and which the federal government declared flatly infeasible back in 2011.

Go look at: two photographs, a Bigg's and a Southern Resident, both taken at distance in ordinary grey light. Decide honestly whether you could tell them apart from a moving boat. That judgment is what the whole rule rests on.