Three months into a Jet Ski trip around the U.S., two brothers hit L.A. Then their escort boat is stolen, leaving them . . . : High and Dry

Sharks circling beneath him in Florida didn’t stop Gary Frick. Neither did the hidden sandbar that snagged him off Louisiana. Or the fisherman who tried to hook him and reel him in off New Jersey.

It took some dirty rats in Los Angeles to halt the man who has spent the past three months trying to circumnavigate the United States on a Jet Ski.

When Frick and two assistants ended a three-day Los Angeles stopover on Thursday and tried to resume his grueling ocean ski trip, they discovered that thieves had stolen the escort boat that is accompanying the Jet Ski.

Frick, 34, of Ocean City, Md., had chained the $10,000 jet-powered Zodiac speedboat to a light pole at Marina del Rey while he and his assistants visited patients at Childrens Hospital of Los Angeles.

The 5,040-mile ski trip started in Maine on May 8. It is being staged to promote awareness of the Children’s Miracle Network, a group that raises funds for 165 pediatric hospitals across the country. The trip had been scheduled to end in Seattle on Labor Day.

The escort boat was being piloted by Frick’s 22-year-old brother, Craig. It carried fuel and emergency supplies for the Jet Ski. Food and other equipment is being hauled in a motor home that is being driven by Kevin Lamb, 29, of Bethany Beach, Del.

“I don’t believe this,” moaned Frick. “We’ve gone too far to stop now. We only have 1,300 miles left. We can’t shut the trip down now.”

Frick had planned to ski from Marina del Rey to Santa Barbara on Thursday. From there, he intended to ski to Surf, Calif., today. On Saturday, he planned to ski to Morro Bay.

Instead, he hopes to lease a replacement Zodiac today and resume the trip Saturday.

“I can’t be riding into Seattle at the end of October with snow falling around me,” Frick told Los Angeles County Sheriff’s Deputy Bob Cordoza, the harbor patrolman who took a stolen boat report from him Thursday.

“We’ve gone through some pretty nasty towns without problems. We didn’t expect any here,” Frick said, glancing around at yachts moored at the posh Westside marina.

The Jet Ski odyssey began in 38-degree water in South Lubec, Me. Covering about 70 miles of shoreline a day, the Kawasaki 650SX had averaged about 20 m.p.h.--despite eight-foot swells off Cape Hatteras and a bone-jarring Pacific Ocean chop “that’s like the ski hitting solid concrete,” Frick said.

“My hands feel like I have arthritis now. You get so tired standing up and holding the handle pole that at the end of the day your arms are like rubber.”

The trip to Los Angeles was filled with surprises.

An angry fisherman on a jetty near Asbury Park, N.J., tried to hook Frick with his rod and reel. When Frick stopped the ski, the man challenged him to a fight.

Other encounters with fishing hooks were scarier: A fishing line snagged Craig Frick by the neck near North Carolina. He freed himself without being yanked overboard. But by the time he untangled the Zodiac, about 1,500 yards of some unsuspecting fisherman’s line had been unreeled.

Gary Frick ran his Jet Ski over hammerhead sharks off the Florida coast. Lightning bolts threatened the brothers on the Gulf of Mexico. So did a sandbar hundreds of yards from shore that was hidden by chocolate-brown gulf waters that were only a few inches deep.

In New Orleans, the brothers got lost after nightfall on the Mississippi River. Lamb used a two-way radio to talk them to safety at a riverfront steel mill.

The boats were hauled by trailer from Texas to California.

The trio had no problem with thieves until last weekend, when they reached Long Beach. There, someone stole a cheap waterproof watch that was attached to the Jet Ski’s handlebars, Gary Frick said.

Then came Marina del Rey.

Frick speculated that thieves may not have gotten far with the 800-pound speedboat, which is gray and bore the license number MD 6844 B. The words “Coast to Coast for Kids” were printed on the sides with removable letters.

The Zodiac was atop a lightweight trailer equipped with fat “beach tires” that are unsuitable for paved roads, he said.

“We can’t continue without it,” said Frick, an electric company owner who is footing the $50,000 cost himself. “The ski only gets about six miles to the gallon. I can’t just pull up onshore and fill up every time I run out of gas.”

But Frick vowed Thursday that he will keep going. Even if it means walking on water to do it.