LockPush answers one question: how long will a recreational boat wait at the Ballard Locks? It is free, has no accounts and no ads, and is built and operated by Clear Fountain LLC — the maker of TidePush, the Pacific Northwest tide and current passage planner.
Waits decompose into a mechanical chamber cycle (median 18 minutes, fitted LogNormal) and a demand-driven queue, modeled as "make this cycle or miss it": measured, ~60% of boats make the next cycle and ~33% wait one more. Estimates are medians of the last 30 days for your hour band and direction, scaled by how the lock is running today (queue pace and chamber pace measured separately), plus a full-cycle penalty when commercial traffic — which legally locks first and never shares the small lock — is scheduled or observed approaching. Calibration is checked on held-out days: the 10–90% band caught 79% of actual waits (target 80%).
The model only keeps terms that survive the data. Two that didn't: "a big batch drains the queue" (reversed — big batches mark rush periods; waits after them run longer, which the forecast now uses as a rush signal) and "high tide shortens the cycle" (~0.07 min/ft after controlling for time of day — no tide term exists in LockPush).
The Corps logs recreational boats as anonymous grouped records, so nobody can count individual boats from the feed; records appear only after a lockage completes; closures, low-water operations and staffing can push waits far past any forecast. LockPush is planning guidance, not official lock status and not a navigational authority — see the terms.