Simple Tide Predictor – Online Approx High/Low Times
Enter a reference port's high tide and see estimated tides for the next 3 days using rule of twelfths. Educational.
UD5 Toolkit
Enter a reference port's high tide and see estimated tides for the next 3 days using rule of twelfths. Educational.
Select month and hour to see a simple star map with major constellations labeled. Educational astronomy fun.
List of major annual meteor showers with next peak date and moon phase prediction. Stargazing planner.
Answer simple questions (color, size, beak shape) to narrow down common North American backyard birds. No photo needed.
Use browser compass and geolocation to show which planets and stars are overhead. Minimal, local only.
Shows today's moon phase, age, and percent illuminated. Simple visual display. Works offline.