The official first anniversary for the opening of South Pacific was April 3, but the party to commemorate the occasion wasn't held until this past Sunday, April 26. This was to the delight of everyone concerned - the cast (original and replacement), the crew, LCT staff, and friends of the production. The rooftop setting for the affair, at a club on Fifth Avenue, would have been wasted without a summer-like sundown as the celebration got underway, and the suggested dress for the occasion -- "semi-tropical kitsch" -- would have made much less sense without the more-than-semi-tropical heat that moved into Manhattan for the weekend.

Among those who chose to comply with the sartorial hint were Loretta Ables Sayre (Bloody Mary), whose own tropical touch (she supplied authentic leis from her native Hawaii for last year's opening night) has been a constant during the show's run, and Bert Fink, of the Rodgers & Hammerstein Organization, who told me during our saunter through the party's tasty buffet that his print shirt was authentically Hawaiian enough to be worn by some Honolulu businessmen to the office.

Some of the Seabees chose less floral, but no less summery attire. Crisp in a white-linen shirt, Robert Lenzi told me he couldn't believe how fast the first year had gone. "On the one hand, it seems as if we were in rehearsal only yesterday. On the other hand, so much has happened offstage since we started: Kelli [O'Hara] got pregnant, Jerold Solomon's gotten engaged. We've all gotten to know each other really well, and we still like to hang out together. We all feel really lucky to get up every day and go to a job that we love."

Such gratitude was a theme sounded not only by current cast members but by those who've moved on. Zachary James, who landed the role of Lurch in the upcoming Broadway musical of The Addams Family, has been out of Seabee blues for two weeks but he's still in a little bit of a withdrawal. "It's hard. You get used to being with all the guys every day and I miss that. At the same time, I think my body is happy to have a rest from the physical demands of the show."

Physical rigors were also on the mind of Karen Olivo, whose performance as Anita in the current Broadway revival of West Side Story has been generating Tony buzz. On the arm of her husband -- Matt Caplan, the show's Professor -- Olivo looked over the rooftop crowd and said, "Being part of a two-show family has its demands. Thank goodness Matt goes home every night having done something he's enjoying. You don't want to take that for granted."

Later in the party, as I surveyed all the instinctively easy interactions between members of the vast South Pacific team, I was struck both by the oak-like hardiness of the group and its hothouse-flower delicacy. You've got to be tough to finish a five-show weekend and then have the energy to party into the night. (The kids in the cast bounded around the club's dance floor with such energy that I wondered if they'd been imbibing Red Bulls.) At the same time, the chemistry required to keep all the talent in a show not just in sync but happy after 480 performances sometimes feels like a miraculously fragile thing.

In the end, that yin-yang formula may not be fully graspable to those outside it. It reminded me of Willa Cather's description in her novel My Antonia of why certain experiences -- in Cather's case, growing up in a small town -- can never quite be understood by those who haven't had the experience: It is "a kind of freemasonry."

Unlike freemasons, however, Seabees like to party.

BRENDAN LEMON is the American theater critic for the Financial Timesand the editor of