Sirena Yachts just announced that its new entry-level 48 flybridge will make its U.S. debut at the Palm Beach show, starting March 21. The 48, designed, like all previous Sirenas, by the acclaimed Argentinian naval architect Germán Frers, made its global debut at the Cannes show in September. Since then, Sirena has sold 27 of them, including 13 to American buyers. The new 48 is the smallest Sirena to date, in a fleet that includes a 58, 68, 78 and 88. “This expansion into the 40-foot sector will complete our lineup in the most competitive area of the market,” said…