What trimaran warships gain and give up

What are the advantages and disadvantages of trimaran warship designs?

They promise space and stability, but their combat value is poorly demonstrated and even possible ancient precedents are difficult to interpret.

Trimarans offer deck area and stability, but modern trimaran warships have little combat record. Possible ancient precedents are also disputed. Descriptions of very large oared ships may refer to several hulls, several banks of oars, or several rowers per oar, and the evidence does not settle the question.