Online alarm clock for 12:51 am
While you watch the minutes for the scheduled tide reading at Napier’s wharf, set the alarm for 12:51 am so your attention does not drift before the moment arrives. That leaves enough time to have your notes and torch ready before 1:00 am, without repeatedly checking the clock as the hour turns.
Your Napier tide check depends on hearing the signal, so confirm that silent mode is off and set the volume at a level you can notice near the wharf. A quick test alarm can reveal whether the browser’s sound is muted. The alarm cannot protect the tide reading if its page is closed or the phone goes to sleep, because no signal may play at 12:51 am; keep the page open and the phone awake until you have recorded the measurement.
A late-night visit to the Napier waterfront can disturb people at home before you even leave. Prepare your jacket, keys, notebook and torch earlier, then keep the 12:51 am alarm close enough to hear at a moderate volume rather than letting it carry through the house. If someone else is sleeping nearby, use vibration as a backup, place the phone on a firm surface beside you, and move quietly when the signal sounds.