Kayaker makes his way across Gulf of Mexico

MEXICO CITY (Reuters) - An American kayaker seeking to become the first person to paddle alone across the Gulf of Mexico is expected to land on the Louisiana coast on Friday, supporters said Wednesday.

After paddling for 19 days alone at sea, surrounded by sharks, kayaker Arthur Hebert was just 55 miles south of Grande Isle, La.. He set out on May 16 from Isla Mujeres island off Mexico's Caribbean coast.

"He's tired, and has huge sores on his hands and rump, but is doing well," Andrew McAllister, a member of Hebert's support team, told Reuters in a telephone interview.

"This is not the longest open ocean kayak trip, but we believe it is the first time anyone has crossed the Gulf unassisted," said McAllister, who works with Hebert at a construction firm in Louisiana.

He said the Guinness Book of Records was double-checking the feat.

McAllister said Hebert hoped his trip would raise awareness of juvenile rheumatoid arthritis, a debilitating disease from which his 19-year-old daughter Nicole suffers.

In his 17-foot kayak, Hebert is carrying a first-aid kit, two hand-held desalinator pumps for drinking water, bags of dried fruit and nutrition bars for food, a VHF radio, flares, binoculars, lifejackets and a satellite-based Global Positioning System (GPS).

He has a small radar reflector perched on the back of the craft, and communicates through a portable digital tracker called Argos, which continually beams his position to satellites. He can also hit preset buttons to send messages ranging from "all is well" to "send help."

Hebert takes brief naps by day and stays awake at night to avoid getting hit by passing oil tankers or sucked into their draft.

When he is not paddling, he spends much of his day pumping sea water through his portable desalination machine.

His only defense against sharks and poisonous jellyfish has been a six-foot hand-held spear.