Hot answers tagged 16th-century
For battle plans and such, they used dispatch boats (which they then called "Aviso" or "Adviso", as in advice boat). These would carry orders from shore to ship and from ship to ship. For maneuvers, like Pieter said: flags and horns. Lanterns at night for guiding purposes - as seen here, resulting in a scattered English fleet when Drake snuffed it for more ...
Only top voted, non community-wiki answers of a minimum length are eligible