Glossary: A

11 terms.

• Able Seaman
  Certified deck rating with a minimum of 18 months sea service, competent in watchkeeping, mooring, and cargo handling.
• AIS Class A
  The mandatory AIS transponder fitted on SOLAS ships transmitting vessel data at regular intervals and responding to interrogations.
• AIS Class B
  A lower-power AIS transponder used by smaller non-SOLAS vessels, transmitting position and identity data at reduced reporting rates.
• Anchor Handling Tug Supply Vessel
  An offshore support vessel designed to tow and position mobile drilling rigs and handle anchors in deepwater operations.
• Anchorage
  A designated area with suitable holding ground where a vessel anchors to wait for a berth, tide, or clearance.
• Angle of Loll
  The angle at which a vessel with negative initial stability comes to rest on her side as she cannot return to upright.
• Annual Survey
  A classification inspection conducted each year to confirm that a vessel's hull and equipment remain in a satisfactory condition.
• Automatic Identification System
  VHF transponder system that automatically broadcasts vessel identity, position, course, and speed to nearby ships and shore stations.
• Auxiliary Engine
  A diesel generator engine providing electrical power for shipboard systems independent of the main engine.
• Azimuth
  The angular bearing of a celestial body measured clockwise from true north, used to check compass error.
• Azimuth Thruster
  A propulsion unit that can rotate 360 degrees, providing both thrust and steering without a conventional rudder.