Underwater robotics is a growing field in which more research is required. A literature review has been conducted on underwater robotics, focusing on the swarm problem with this type of robotics to help overcome this gap. Consensus control of robotic swarms is focused on, with a brief description of formation control and how it can be applied in the underwater setting. The basic concepts behind Particle Swarm Optimization, Ant Colony Optimization, Bees Algorithm and Heterogeneous Swarms has also been presented. The problems that are associated with communicating underwater are shown, with some possible solutions to this problem also being presented. Possible future work is described to conclude the paper.