Unusual 700 W mercury lamps

The picture above shows a series of rather unusual 700 W high-pressure mercury fluorescent lamps (an uncommon wattage in itself) which differ from each other by the nature of their fluorescent coating and their country of origin, showing completely different design strategies. From left to right we have a marine green Singaporean Acelux HF700 coated with alpha calcium orthophosphate, a Polish Polam LRF700 coated with a blend of zinc calcium orthophosphate and yttrium vanadate, and then a Soviet Russian MELZ DRL 700(10) coated with yttrium vanadate. While the last two lamps are meant for general lighting applications, the first one was designed specifically for luring fish to the surface, a common fishing practice in South East Asia.