Links:

Boatswain's whistle – different signals and their meanings, with audio

Marine Institute – choose from 24 topics designed for teachers and students

Maritime signal flares – invention

Patterns of communication – a web-based activity for grades 5 and 6

Phonetic alphabet – this code was initially used by the Navy to clarify communications

Pyrates code – use the decoder machine to print out a message for a friend to decode

Semaphore flags – translate

Semaphore flags – alphabet and information.