Escallop Shell - One who has made long journeys or voyages to far countries, who had borne considerable naval command or who had gained great victories.
Whether grey or blue skies lay overhead, the heft of the waves was always huge – sometimes rhythmic and pleasant, at others offering a waltzer of a voyage.
Sophisticated instruments which were to make possible the European voyages of discovery, such as the astrolabe , the quadrant, and good navigational maps, were also developed by Muslims.