Most important wars in the Ancient Mediterranean had a major naval component.
It can be argued that the collapse of the Western Roman Empire in the 5th century AD was caused, or at least massively hastened, by two negative naval events:
a) the Battle of Cartagena (461), where the Roman navy was defeated by the Vandals, partly due to some captains being corrupt [0]. This prevented Majorian, the last great Western emperor, from reconquering North Africa;
and
b) the Battle of Cape Bon (468), again a massive failed effort to crush the Vandals [1]
It is somewhat obscure to modern readers, but Vandals were probably more dangerous at sea than on land.
It can be argued that the collapse of the Western Roman Empire in the 5th century AD was caused, or at least massively hastened, by two negative naval events:
a) the Battle of Cartagena (461), where the Roman navy was defeated by the Vandals, partly due to some captains being corrupt [0]. This prevented Majorian, the last great Western emperor, from reconquering North Africa;
and
b) the Battle of Cape Bon (468), again a massive failed effort to crush the Vandals [1]
It is somewhat obscure to modern readers, but Vandals were probably more dangerous at sea than on land.
[0] https://en.wikipedia.org/wiki/Battle_of_Cartagena_(461)
[1] https://en.wikipedia.org/wiki/Battle_of_Cape_Bon_(468)