SHM for Windows is a Windows-based tidal prediction program, using the Simplified Harmonic Method (SHM) of tidal prediction.
Users simply enter the harmonic constants for a particular port (as referred to in Admiralty Tide Tables and NP160 - Tidal Harmonic Constants) and predictions are displayed as a graph of height against time for a period of up to 24 hours, for a maximum of seven consecutive days.

A major advantage of the program is the ability to store harmonic constants for any number of ports across the world, making SHM for Windows invaluable for both the professional mariner and recreational sailor.