Stealth ship

Although radar cross-section (RCS) reduction is a fairly new concept, many other forms of masking a ship have existed for centuries or even millennia.

A stealthy ship shape can be achieved by constructing the hull and superstructure with a series of slightly protruding and retruding surfaces.

Despite being 40% larger than an Arleigh Burke-class destroyer, its radar signature is more akin to a fishing boat, according to a spokesman for Naval Sea Systems Command;[1] sound levels are comparable to the Los Angeles-class submarine.

The Royal Navy's Type 45 destroyer has similarities to the Visby class, but is much more conventional, employing traditional steel instead of carbon fiber.

Modern warships emit much electromagnetic radiation in the form of radar, radio, and bleed-off from the ship's electrical systems.

The most common method is to mix any hot gasses emitted by the main source of heat—the engines' exhaust—with cold air to dilute the signature and make it harder to pick out the ship from the background warmth.

This area is probably the oldest form of stealth, with records going back almost as far as the writing of ancient mariners using visual tricks to make their ships harder to spot.

Composites like fiberglass and carbon fiber are effective blockers of radar and give smaller vessels an advantage in further RCS reductions.

To compensate, a ship may include a coating of a radar-absorbing material, although this can be expensive and may not stand up to the corrosive effects of salt water.