Free tide-cycle tool
How tides work, shown in motion
Explore how tides work with a moving Earth, Moon, Sun, tide curve, spring and neap range, and rule-of-twelfths view. It is an independent revision aid, not official RYA training or assessment.
Direct answer
Tides are mainly driven by the Moon and modified by the Sun, local coastline, seabed shape, and weather. Most UK tide work for small craft uses published high and low water times and heights, then interpolates between them with a curve or the rule of twelfths.
- Best for
- Lunar day, springs, neaps, tide curves
- Includes
- Play, pause, scrub, and speed control
- Practice mode
- Animated model, guided lesson, quiz
- Cost
- Free, no login required
Last reviewed: 2026-07-08Richard Moore
Springs, neaps, tidal curve
Tides in motion
Scrub one linked clock to connect the Moon's geometry, spring-neap range, the harbour gauge, and the familiar tidal curve.
Moon phase
0%
Range
Spring