When you invest in a set of marine speakers for your boat, it is important to make sure that they receive the power they need to perform at their best. When you are looking over the specifications it is important to notice the RMS (or "continuous") power rating. The RMS power is usually expressed as a range "25 - 60 watts RMS " for example. The higher number represents the maximum RMS driving power at which the speaker will operate without any reduction in audio quality or damage to the speaker when played over a long period of time.