Not long ago a boat's entertainment system consisted of a small portable radio, possibly with a built-in cassette tape player. Today's on board entertainment systems can be whatever you want them to be and on larger yachts rival the most exotic home systems. Smaller vessels can install high performance systems based on advanced automobile system technology. Open vessels can select from a number of marinized automobile radio / tape / CD systems that are specifically designed to cope with high humidity and an occasional splash of spray. TV options include small screen LCD and CRT units, some with built-in VCRs. The extraordinary space saving of flat screen displays is making them increasingly popular, although at present they are quite costly in comparison to conventional CRTs. Flat screen, plasma displays measuring up to 50 inches are often seen on large yachts. The ultimate entertainment system limit is financial, not technical.

As always, the loudspeaker is the weak link in any sound system. While the design of circuitry is a matter of precision engineering, loudspeaker design is much an art. This is especially true on a boat, where space is at a premium and the moist, often salt laden atmosphere is hostile to many speaker cone materials. Except for installations entirely within an interior cabin use only speakers listed by their manufacturers as suited for marine use in an exposed location.

Speakers contain strong permanent magnets whose stray fields can extend for distances that can exceed three feet. These fields are usually strongest in a plane extending from the back of the cone, parallel to the surface on which the speaker is mounted. Magnetically shielded speakers are available and should be used if the speaker must be located close to the helm or the autopilot's heading sensor.

Television is increasingly a part of boat entertainment systems. Off the air program choices include conventional home style antennas, special omni-directional or automatic signal tracking marine antennas and various types of satellite antennas. The latter are either fixed mount units best used when installed on a dock piling or servo driven, automatic tracking units. VCR's and especially DVD's are widely used on boats. Some boat owners use their computers to play DVDs, viewing the programs on the computer's monitor or with a converter, on a TV set.

Regardless of the type of entertainment system you choose, remember that they consume electrical energy. Although the drain may not be too large, even a car radio can flatten a battery if run too long.

Comments about on board entertainment systems would not be complete without a plea for their sensible use. Taste and preference in music is an intensely personal matter. What is music to some is nothing but irritating and annoying noise to others. Many of our audio systems have sufficient power to deafen people on boats quite far from our own. Sharing our pleasure with others is laudable but sharing our taste in music with an entire anchorage or marina is neither good manners or, given the presence of flare guns on may boats, a safe practice.