An amplifier, for marine life or else, has the soul purpose implied in its name: amplifying the sound provided by your stereo speakers. Sound, especially on boats, have to fight engine noise, splashing sounds, and the talk and commotion of the people on board. Adding an amplifier to your boat system is a good idea.

Adding an amplifier is essential to experience great sound from your audio system. An amp adds the wattage to your audio system that a receiver lacks. An amplifier delivers clean power that drives your speakers and is designed to get out of them the best sound possible.

A good amplifier is one that won't compromise sound quality for the sake of volume. They'll do the trick of outshrieking all the non-music noise, while maintaining superb quality.  

All this is as far as amplifiers go. Boat amplifiers have some additional features necessary for it to survive and thrive in the marine environment and harsh conditions they might encounter on their voyage. They'll have to be shielded against the unforgiving UV-rays, sprays and moisture, as well as resist rust. On top of that, it's advisable to look for amplifiers equipped with the ability to resist the vibration inherent for boating.

In short, marine amplifiers should be good amplifiers; plus, you want them featuring circuit-boards coated with moisture barriers and heat-sinks with marine grade UV-resistant  finishes.

Remember, that boats often play music for extended periods while having the engine turned off. The engine charges the batteries, so no need to worry about blasting music with the engine on. However, playing music with the engine off leaves your equipment at the mercy of the batteries, which means that optimizing energy consumption is of utmost importance. Be sure that your amplifiers are connected to 4-ohm speaker loads, as 2 or 1 ohm will consume more battery power. Also, make sure to install your amplifier in a location with adequate air circulation.

Some of the common marine applications for amplifiers include the 1. two-channel amplifier, 2. multi-channel amplifier, and the 3. mono amplifier. Let's discuss them in some greater detail.

Two-channel Amplifier. This one powers two speakers, with each channel powering a single coaxial or component speaker.

Multi-channel Amplifier. This is what you're looking for when dealing with amplifying a complete system. The way it works is quite simple and intuitive. Four-channel amplifiers power four coaxial or component speakers, while A five-channel amplifier adds power on the fifth channel for a subwoofer. Six-channel amplifiers are even more flexible -- they'll power six speakers or four speakers and a subwoofer, which is done by bridging channels 5 and 6.

Mono Amplifier. A mono amplifier is meant for one or more subwoofers.

At the very minimum, a good marine amplifier should come with the following features:

• Class G/H topography, which grades it very power efficient.
• Overheat proof, preventing the device from overheating.
• Compact chassis design, making it smooth and easy to install.
• Marine-grade component and electronics, such as UV-resistant and coated beard, for making it water- and corrosion-resistant.
• Equipped with an internal cooling fan.
• protected against thermal overload and reverse over/voltage.