The event was put together by the Coast Guard and the Lucile Packard Children's Hospital as "an opportunity for the kids to go out and feel a little normal and watch the aerial acrobatics," hospital spokesman Todd Kleinheinz said.
The boys, who range from 12 to 16 years old, have been treated in hospital's oncology clinic, Kleinheinz said.
They were picked up from the hospital in a white stretch Hummer limousine paid for by local charity 19 For Life, and were taken to Yerba Buena Island in San Francisco to board the Coast Guard Cutter George Cobb.
The boys will then go out on the bay to watch the Navy's Blue Angels demonstration squad do its practice runs in their distinctive royal blue jets.
The /*Blue Angels*/ were formed in 1946 as a naval demonstration team meant to maintain public interest in the Navy, according to their official military Web site.
Kleinheinz said that the boys "were really pumped up" when the limo came to pick them up this morning.
None of the boys had seen the Blue Angels in person, and "were really excited to be out on the water," Kleinheinz said.
"It's just a great opportunity to get a group of guys who've shared the same experience to go out and have a full, fun day together," he said.