How to use the online timer
You have started a second twenty-one-minute countdown while your narrowboat waits to pass through the canal lock again. Keep the boat steady near the landing, watch the crew working the gates and leave enough room for anyone coming out of the chamber. The repeated interval gives you a useful window without assuming that every lock cycle will move at the same pace.
Beside a running engine, rushing water and conversations from nearby boats, the signal may be hard to hear. Keep your phone somewhere secure but close enough that its alert is not buried by background noise, rather than leaving it inside the cabin. A vibration against a solid surface can provide another noticeable cue while you continue watching the lock and holding the line.
For the second run, treat the countdown as a fresh estimate rather than proof that the next passage will match the first. A volunteer lock keeper, a boat travelling the opposite way or a low pound can change the wait. If the gates open sooner, stop the remaining time once your crew is ready; if they stay closed, restart only after checking what is actually delaying the passage.
Common questions
Why might this canal-lock wait take longer or shorter than the set interval?
Gate operation, water levels and boats approaching from the other direction can all alter the timing. A staffed lock may also move differently from one worked entirely by boat crews.
What should I do if the narrowboat has not entered the lock when the second countdown ends?
Stay in the safe waiting position and check the gate, paddles and instructions from the lock keeper or crew. Begin another interval only if the expected delay makes it useful.