WALTHAM, Mass. (AP) _ A barge loaded with equipment for a nationwide project to bring the thrill of deep-sea exploration to students sank off Ecuador, officials said Friday.

Nobody was on the barge when it sank Thursday about 400 miles west of Ecuador as it was towed by that country's navy. Millions of dollars in equipment was lost and the future of the expedition was in doubt.

The Jason Project, conducted by the Jason Foundation for Education, had planned a two-week expedition beginning Dec. 2 from the Galapagos Islands. More than 500,000 middle school students at 20 receiving sites in the United States and Canada were to have watched, said Becky Squires, a foundation spokeswoman.

''We're devastated,'' said oceanographer Robert Ballard, the expedition leader. ''There's just no other word to describe it.''

The cause of the sinking was under investigation, Squires said.

''Most of those students have been studying a curriculum on the Galapagos for a long time,'' Squires said. ''Clearly it'll be a disappointment for all of them.''

The Waltham-based project, in its third year, broadcast scenes from past scientific expeditions on the Turner Broadcasting System's cable network to students in schools and museums.

Lost with the barge was an underwater robotic vehicle known as Jason Jr., satellite communications equipment, broadcasting apparatus from TBS and scientific gear from the Woods Hole Oceanographic Institution, Squires said.

The underwater robot was used to explore the Titanic. The wreck was found in 1985 by a team of French and Americans, of which Ballard was a leader.

The $4 million Jason Project had traveled to the Mediterranean and Lake Ontario.

Students would have been able to see and talk with scientists at six sites on land and in the sea as part of the December expedition. A geology lesson would have been set at an active volcano and Jason Jr. was to have probed the ocean depths to show how molten rock wells up to create a new sea floor.

Shelley Lauzon, a Woods Hole spokeswoman, said sponsors of the project - including the National Geographic Society, EDS Corp., Cray Research and the National Science Teachers Association - were deciding whether there was a way to continue the expedition.

Lauzon estimated the loss of equipment at several million dollars.

''There's little hope of salvaging the gear,'' she said. ''It's in about 9,000 feet of water.''