Firstly, submarines would lose one of their biggest advantages, anybody will be able to spot them. Secondly, predators will probably increase in number, it will be difficult for fishes to hide, there will be complete chaos everywhere. Thirdly, temperature of oceans will rise as transparent oceans mean more sunlight, this might be good news for plants which perform photosynthesis but very bad news for much of marine life which will not be able to adjust to this increase in temperature. Fourthly, it might prove to be a doubleedged sword, while hidden treasures might reveal themselves but at the same time tons and tons of human generated waste hidden inside oceans will suddenly become visible. Lastly, marine life which has evolved in darkness might find it difficult to adopt.