The 180 meter long, 46866 dwt oil tanker High Power suffered an explosion while off Gibraltar.   The tanker had left Tuzla and proceeded to Gibraltar where it stopped to take on fuel from the bunker vessel Aegean Princess.  During the transfer of fuel, the High Power had one of its boilers exploded releasing a large plume of black smoke into the air.  There were no injuries and no fire.  The vessel contacted the authorities stating they had everything under control. The local authorities dispatched emergency services as a precautionary measure.  The vessel was detained until a detail account could be provided by the crew.  No reports of pollution being released.