Miami ? Weatherbeaten and windblown, a Spanish aristocrat will putter into the Miami Beach Marina today ending a four-month jet ski journey on the high seas.

Alvaro de Marichalar y Saenz de Tejada, who turned 41 while crossing the Atlantic, is expected to arrive at the marina about 10 a.m. CDT 117 days after leaving Rome aboard a jet ski.

The purpose of the trek: raise money and awareness to fight drug addiction and help the elderly in Latin America.

The dashing Marichalar’s exploits chronicled on his Web site www.ocean2002.com also have prompted a few dozen postings from female admirers bidding him bon voyage.

“He’s a very coveted bachelor,” said longtime friend Riccardo Olivieri, president of South Beach developer The Bentley Group, the American sponsor of Marichalar’s “Atlantik2002” effort.

Marichalar’s parents are both titled aristocracy and his brother is married to Princess Elena, daughter of Spain’s King Juan Carlos and Queen Sofia.

“At parties he’ll grab a microphone and sing better than Julio Iglesias,” Olivieri said.

But the odyssey required a bit more stamina than a society soiree.

Marichalar, who has made similar journeys across the Panama Canal and the Straits of Gibraltar, had to gain 40 pounds to beef up for the 5,500-mile trip. He traveled aboard a twin-engine Bombardier Sea-Doo navigating 12 to 14 hours a day through often-choppy seas and frigid temperatures.

He towed a hi-tech, enclosed raft equipped with shark-repelling sonar to sleep in.

A support boat followed across the sea, carrying food and fuel.

He’s passed the Canary Islands, skirted the Azores off the coast of Africa and waited out repairs to his “nurse” ship in Antigua.