After 12 years and thousands of missions, Brothers to the Rescue is suspending its search-and-rescue flights, its mission made almost obsolete by smugglers' speedboats and changes in U.S. immigration policy.

José Basulto, founder and leader of an organization that lost four volunteers and two planes when they were shot down by Cuban MiG fighter planes in 1996, announced Tuesday that the organization was grounding its flights over the Florida Straits.

The once-celebrated group can no longer afford to fly missions that are rarely needed, he said. ''We are simply not as necessary as we have been in the past,'' Basulto told The Herald.

``It is redundant work on account of the fact that the U.S. Coast Guard is providing a very effective surveillance around the shores of Cuba that we cannot compete with.''

For more than a decade, the group's volunteer pilots patrolled the Florida Straits, often bringing the first glimmer of hope to floundering migrants when they caught sight of the planes.

But the evolution of how people escape from the island has lessened the urgency of the Brothers' airborne mission.

Where Cubans used to flee on often-makeshift rafts that came to symbolize their desperation, in recent years they have come to rely more on smugglers and organized boat trips.

Hermanos al Rescate, as they are known in Spanish, began in 1991 with 10 planes and 36 pilots. They spotted 224 migrants in the first year. In its heyday, the group conducted 32 weekly missions, Basulto said.

The flights were cut to 16 a week, then to four a week, then to strictly Saturdays before their current emergency-only status. Today Brothers has just two planes and four pilots.

TURNING POINT

The organization was already at a turning point in 1996 when Cuban fighter planes shot down two Brothers' aircraft. Changes in U.S. immigration policy a year earlier had made the group wary of alerting the Coast Guard to rafters adrift in the Florida Straits because most would be repatriated to Cuba rather than delivered to U.S. shores.

Instead, Brothers were spending more of their resources printing anti-Castro leaflets and sometimes dropping them over the island.

Donations were declining.

Then on Feb. 24, 1996, as three Brothers Cessnas flew about 25 miles off the Cuban coast, Cuban MiGs fired at them. Two planes were shot down; only the aircraft piloted by Basulto survived.

The shoot-down was followed by revelations that the organization had been infiltrated by Cuban spies. Basulto became estranged from the families of the men killed in the shoot-down. Money and volunteers became increasingly scarce.

In the past several years, the Coast Guard and the exile group have worked hand in hand to find lost vessels -- whether they were rafts or smugglers' boats, and whether their passengers were Cubans, Haitians or even U.S. citizens lost at sea. The missions have been only on demand, however -- when families reported missing relatives. There have been no scheduled flights in two or three years.

Their last flight was two weeks ago, a response to a call from the worried child of a Naples man who had not returned from a fishing trip. The search was fruitless. The men's bodies were recovered days later.

Coast Guard Lt. Tony Russell said the agency would miss the extra eyes. ''In this time of homeland security when we're asking people to look out more or report things that are suspicious, any time we lose a source of information it's certainly going to have some impact,'' Russell said.

``It certainly doesn't hurt when they're out there helping. At the same time, we don't consider Brothers to the Rescue a Coast Guard resource.''

Nor does Basulto want them to. ''Our mission was always twofold,'' he said. ``First to save lives and then to provide an opportunity for Cubans to be free. We don't want to be part of the Coast Guard's new agenda, which is to send these Cubans back. They have become Castro's border patrol.''

The Brothers' change in focus is understandable and welcome, said U.S. Rep. Ileana Ros-Lehtinen, whose early championing of the group earned her the nickname ''la madrina'' -- or godmother -- from Brothers' pilots.

''Brothers to the Rescue was a pioneer organization. So often those planes were the first to spot rafters before they even came under the radar of the Coast Guard,'' she said.

NEW PRIORITIES

Now, Basulto says, he does not want the Brothers' service to provide a false sense of security. ``Brothers to the Rescue is becoming day by day more like the Lotto. If we find somebody out there, it's a miracle.''

''This is the moral thing to do. If only to stop the perception that we are that safety net that may make somebody jump into the sea, I think it was time to call it off,'' he said.

The costs of running the operation -- hangar rental, maintenance, insurance -- are also a big factor, he said.

The Brothers will continue to seek funds from the community, but for other projects, he said. They will continue to support the opposition movement in Cuba, publish leaflets on nonviolence and civil disobedience and smuggle them to the island, and press for an indictment of Fidel Castro.

The publicity generated by Brothers to the Rescue over the years has helped highlight human rights abuses in Cuba, Ros-Lehtinen said.

''Their strategy may have changed, but their mission remains the same,'' she said.

``They are still searching for a free Cuba.''