Assassin's Tribe Harpoon Gun

Its 300 years further in the future on Earth and sea levels have risen and engulfed all the land with it. Human population on earth now live underwater in sea bases and have dropped to 10% of what they used to be. Because food is hard to come by, what is left of the humans have taken up territory and been divided in to clans in order to survive. Living underwater has stunted the human’s technology and they have made very little progress in their time. The humans have dropped down the food chain and have become survivors in this world. With increased food source for all the carnivorous animals in the water they have multiplied in numbers and have become the dominant predators.
The weapons have not changed much with only a few advancements such as scopes that can detect heat and electrical signals in the water. One of the most affective weapons out there is one used by the Assassins clan. This clan specialise in staying hidden and striking you in any which way. This means that their gu