Web alarm clock for 8:17 a.m.
While you watch the tide line for the right moment to clear seaweed, an alarm set for 8:17 am lets you stop checking the clock every few seconds. The shore can change quickly at low water, so the signal marks your planned start while you keep an eye on the exposed area. There are 43 minutes before 9:00 am, enough time to gather the seaweed you can safely reach and keep track of the returning water.
Because your hands may be wet or busy with a rake, check the sound setting before leaving the phone somewhere dry. Silent mode can prevent the alarm from being heard even when the page appears ready. Also keep the browser running and the phone awake: if either closes down, your seaweed reminder may never sound, leaving you without the cue you were waiting for. A short test alarm beforehand can confirm that the volume is noticeable over wind and waves.
Along an exposed Philippine shore this early, changing cloud and glare from wet sand can make the screen harder to read. Place the display in open shade, raise its brightness only enough to see 8:17 am clearly, and avoid staring at it while waiting. Glance at the large time briefly, then look back toward the water and your seaweed area.