Crabbing off the pier
March marks the beginning of California's crabbing season, and you can get in on the action with a free pier-crabbing demo offered by the National Park Service every Saturday. After class, borrow the free equipment and put your skills to the test. At Historic Fort Port in the Presidio. Saturdays from 10 a.m.-12 p.m., Make a reservation at 415/556-1693. Demonstrations are free.
The St. Patrick's Day Parade
Join in the celebration on March 13 during the annual St. Patrick's Day Parade and Festival. Floats, Irish dancers, and marching bands troop from Harrison and 2 Street in SOMA to the Civic Center, where the party continues outside City Hall with live music, beer gardens, and kids' activities. The city's large Irish population, which includes many expats, has made this the largest St. Patty's Day parade west of the Mississippi. Parade begins at 11:30 a.m.; Civic Center Festival from 11:00 a.m.-5:00 p.m. Head to Market Street between 2 and 6 streets for the best views.
Culture at First Thursdays
On the first Thursday of every month, many of the city's art galleries hold evening receptions featuring artwork from both local emerging artists and the more nationally renowned. Wine flows as galleries stretching from the Mission to North Beach party on (you can download a map at firstthursdayart.com), but the best way to enjoy the night is at the 49 Geary building downtown, home to a dozen or so of the city's top galleries. This month at 49 Geary, make sure to check out photographer Diane Arbus, known for her portraits of the deviant and marginal at the Fraenkel Gallery. 49 Geary, 5:30 p.m.-7: 30 p.m. Free admission.
Organ recitals at the Grace Cathedral
Visitors come to tour the French gothic Grace Cathedral because of its floor labyrinths, soaring stained glass windows, Keith Haring altarpiece, and Interfaith AIDS chapel. But another huge draw is its famous 7,467-pipe organ, which draws renowned organists from around the world. The cathedral hosts a free concert series; this month features soloist Susan Jane Matthews who has played in Europe and the U.S. (including at the Washington National Cathedral). Sunday March 14, 4:00 p.m. 1100 California Street, 415/ 749-6300, http://www.gracecathedral.org
Weeklong Happy Hour
Thanks to Yelp, 25 of San Francisco's most popular bars are holding a seven-day happy hour the first week of March, offering half-priced signature cocktails for about $5, many crafted especially for the event. Some favorite bars taking part are the Michelin-rated, swanky Fifth Floor restaurant, the classic art deco Grand Cafe, the famed Yoshi's jazz club, and Credo, the newest hot spot in the Financial District. March 1-7.