Turn your iPhone into a swell logbook. Measure bearing with the compass, count the sets for period, tilt to measure height. Not a forecast—your read of the day.

Features

• 01

  Measure swell bearing

  Point your phone at the sea and log the swell direction with a magnetic compass. The vertical card reads your bearing—true or magnetic, just like a real hand bearing compass.

• 02

  Count the sets

  Tap as each wave passes and get the period in seconds. SwellBearing calculates the median, so a missed count or double tap won't throw off your measurement.

• 03

  Measure the face

  Aim your phone at the wave trough and crest. The tilt angle and trigonometry give you the height. What you measure yourself, you trust.

• 04

  Speed and wavelength

  From your period, SwellBearing calculates speed (km/h and knots) and wavelength using deep-water wave physics. It's clearly labelled as deep-water values—waves slow and shorten near shore.

• 05

  Log to your spot

  Every bearing, period, height, and your size call—all tagged to the break. Build a record of what you actually saw, over time.

• 06

  Offline, always

  Works completely offline. Nothing leaves your device—no analytics, no ads, no account, no forecasts. The compass, period timer, and height meter run on your phone's sensors alone.

Screenshots