Notes about your surroundings.

Deep-Sea Trawling--Folks who want a real taste of oceanography have their chance this summer, as the Orange County Marine Institute offers three-hour cruises aboard the Van Tuna, Occidental College’s 85-foot research vessel.

“The neat thing about the Van Tuna is it’s a real research vessel, and it’s used by scientists all over Southern California,” said Harry Helling, the institute’s director of education. “It’s kind of a special vessel to be on.”

The craft trawls the deep waters of the continental shelf off Dana Point on Saturdays and Sundays, often coming up with unusual finds that voyagers can examine with the help of the boat’s specialized equipment.

On the cruises, free-floating organisms are collected with plankton nets, while other devices pull up specimens living on the ocean bottom or in the ocean-floor sediments.

Last weekend’s most unusual find, according to Helling, was a salp--a small, gelatinous invertebrate more often found in the warm seas of the Southern Hemisphere. “They look like jellyfish, and they feel like jellyfish,” Helling said. “I would venture to say that most Southern Californians have not seen these.”

Cruises on the Van Tuna are offered Saturday afternoons and Sunday mornings through Aug. 19. The cost is $22 for adults and $11 for children.

The marine institute also offers two-hour dusk cruises on its own 65-foot research vessel, Sum Fun. The cruises depart from the institute at 6 p.m. each Friday through Aug. 24. The cost is also $22 for adults and $11 for children.

The institute is located in Dana Point Harbor, at 24200 Dana Point Harbor Drive. For more information, call (714) 496-2274.