There's no guarantee it was the same man making the calls, but "enough similarities" in the voice and phrasings have led the Coast Guard to investigate the possibility, Capt. Gregory Hitchen said.
A voice expert has been analyzing the calls.
"The voices are indeed similar," the captain told a news conference.
The New Jersey hoax call came in around 4:20 p.m. on June 11. The caller claimed there were three dead, nine injured and 20 in the water off Sandy Hook, N.J.
Nothing was found, and authorities later determined the call came from land.
On May 20, the Coast Guard searched for six people reported missing after a mayday call saying they were abandoning their sinking fishing boat in the waters off Galveston, Texas.
Hitchen said similarities between the two calls include the fact that both came over a high-frequency channel to the Coast Guard "vessel traffic service," not the search and rescue center usually used for distress calls.
The caller in both cases said he was using a "beacon" to describe a hand-held automatic signaling device.
The captain said the caller used "unique language." In addition to words like "souls" describing those supposedly on board, the man in both calls said his antenna was down, and he therefore could not give a precise position. And in both cases, the Coast Guard was told that the people on board were getting into an orange life raft.
Hitchen said the cost to taxpayers of responses to false distress calls runs into thousands of dollars, at least. The "Blind Date" yacht rescue effort topped $300,000, he said. He had no immediate estimate for the Galveston rescue operations, which lasted 36 hours.
The captain said Coast Guard investigators noticed that details in the calls indicated the man "knew a lot about internal Coast Guard operations that you wouldn't find from a typical boater."
But he said he doesn't believe the perpetrator ever worked for the Coast Guard, because of terms like "souls" a mariner doesn't usually use.
Hitchen said all such hoaxes "divert assets from real emergencies."
During rescue efforts for the "Blind Date" hoax, there was one other distress call reporting a person in the water off Bayonne. The Coast Guard responded but found no one. They didn't have a problem mobilizing personnel because it was a small incident, but Hitchen said that if the agency had to respond to a more serious situation at the time, it would have been a scramble.
He said it's important the public be aware of these developments, "so we can generate new leads."
Without witnesses, Hitchen said it's very difficult to solve such cases, but hoax perpetrators "do brag about it in certain cases" - and he hopes that might happen again.