The L.A. Forecast : Swimwear gets glitzier for the cruise season. Ready-to-wear plays fast or loose for spring. : The Wet . . .

What have Madonna, Brigitte Bardot and Gianni Versace got to do with your next swimsuit? Plenty.

Their sexy, sassy, wildly colorful influences dominated the 1992 cruise collections shown at the International Swim and Activewear Market (ISAM), held without formal fashion shows this week in the California Mart.

Once again, Gottex was the exception. It staged a spectacular show Tuesday night at its fund-raiser for Assaf Harofeh Medical Center.

Spectacular is the operative word for the swimwear and cover-ups that will arrive in stores over the next few months. While cruise collections traditionally contain plenty of sparkle, the latest lineup is especially showy. It reflects the growing trend of taking swimwear to the streets, substituting it for bodysuits, bustiers and pretty bras.

Despite the dressy fabrics and opulent trims--velvets, patents, gold lames, Hermes- and Versace-inspired prints, sequins, belts and gold chains--the suits are meant for water.

Robin Piccone’s chain straps, for example, are aluminum and coated with a gold finish that she insists won’t peel off. Decorations play a big part in her collections, meaning she has abandoned her minimalist “scuba influence” for designs that she says are “more feminine, sexy and glamorous.”

Industry emphasis on glamour keeps bosoms very much in view. There are push-up bras, padded bras, underwire bras and even a return to the triangle-shaped bikini bra.

Ready-to-wear-inspired reruns from years past include hot pants--handled especially well by Catalina’s new Cote d’Azur label--and Bardot-inspired ginghams from virtually every company, including Ann Cole.

Cole, an industry veteran, sums up the latest swimwear as “good girl, bad girl. It’s either everything hanging out or everything under cover.”