On the water
Mark rungs, note passage times, and keep a daily summary of how the cruise actually ran.
Tower Lock
A pocket log for canal days: keep lock ladders, boat speed, and a short cruise brief on the phone.
On the device
Notes and plans you enter stay on the phone unless you export or share them. There is no in-app store.
A personal log
Tower Lock is a personal notebook. It does not replace charts, lock notices, or local rules of the waterway.