Where any ship F1aircraft or goods belonging to any of Her Majesty’s subjects, after being taken as prize by the enemy, is or are retaken from the enemy by any of Her Majesty’s ships of war, F2or any of His Majesty’s military aircraft the same shall be restored by decree of a prize court to the owner, on his paying as prize salvage one eighth part of the value of the prize to be decreed and ascertained by the court, or such sum, not exceeding one eighth part of the estimated value of the prize, as may be agreed on between the owner and the re-captors, and approved by order of the court: Provided, that where the re-capture is made under circumstances of special difficulty or danger, the prize court may, if it thinks fit, award to the re-captors as prize salvage a larger part than one eighth part, but not exceeding in any case one fourth part, of the value of the prize.