A thick coat of fog settled over the surface of the ocean. It was a picturesque morning in late December at Pillar Point Harbor, just north of Half Moon Bay, and seagulls were perched in a row on the rooftop of the harbormaster's office.

I was here to fish — for Dungeness crab with a small-boat operator who supplies crab for East Bay markets and eateries. The harbor was lined with row after row of commercial fishing boats with names that were, variously, punny and sweetly earnest: Lost Claws. Lulu. The Out Cast. Pro Fishin't. Stacy Jeanne. Above one boat, there was a big yellow banner: "LIVE CRAB, JUMBO JUMBO SALE." Big crabs sold straight off the boat were going for $6 a pound.

Marc Alley's boat, the Ronna Lynn (named after his sister), is almost certainly the tiniest crab boat that docks at Pillar Point. It's a 23-foot-long blue and white skiff — shallow, flat-bottomed, completely open to the air. Even that description can't quite capture how small the boat looks in relation to the other fishing boats in the harbor, with their fancy amenities — like, you know, a cabin with a roof over it. Put it this way: The first time couple of times I walked past the boat, I didn't even see it. I must have thought it was a liferaft or a little rescue boat that belonged to one of the larger sailing vessels.

Which isn't to take anything away from the fact that it is a marvel of a little boat. Alley, a wiry fellow in his sixties who has been a commercial fisherman for forty years, is something of a renaissance man — a sculptor, electrician, welder, and surfboard designer, in addition to his main line of work. He built the Ronna Lynn more or less from scratch over a period of years, and installed the navigation system and all the wiring himself. The boat is fast and agile, able to dart around tricky waves and get back ashore quickly if foul weather strikes.

The Ronna Lynn isn't big enough to hold a lot of crabs on deck. There was, indeed, barely enough room to fit Alley, his deckhand, me, and Express photographer Bert Johnson. But Alley takes pride in the way he handles the crabs — much more carefully, he said, than most of the boats that are double or triple the size of his. For the bigger boats, speed and efficiency often trump the need to make sure each individual crab arrives at the dock unscathed.

Alley sells many of his crabs on Pier 33 in San Francisco to a wholesale operation run by Berkeley-based Monterey Fish Market, which, in turn ships some of the still-lively, tasty crustaceans to its Berkeley market, and even more of them to some of the top restaurants in the East Bay: Chez Panisse in Berkeley and Pizzaiolo, Camino, and Duende in Oakland, to name a few.

Alley had agreed to bring me and Johnson crab fishing, but he'd warned us not to expect too big of a haul. We were a little more than a month into a Dungeness crab season that's supposed to stretch until the end of June, but he and other small-scale fisherman had been telling me about how 80 percent of the crabs had already been scooped up from the bottom of the ocean within the first two or three weeks of the season, much of them by large commercial fishing boats — large enough to make Alley's vessel look like a toy rowboat in comparison — that had come down from out of state or from ports on the northern coast of California.

In fact, the big operators haul in far more crab in the first few weeks of the season than Bay Area crab lovers can consume. So the large boats sell their catches to giant seafood processors that ship the crab elsewhere — even to China – much of it frozen and packaged for consumers in other states and nations.

As a result, by February or March, there will hardly be any fresh crab left in the Bay Area — for local crab lovers, or for small-boat operators like Alley.

Big boats monopolizing the Bay Area's crab market is not a new problem, but it's gotten worse in the past few decades. A 2001 status report on the Dungeness crab industry by the California Department of Fish and Game noted that prior to 1980, the crab harvest was spread out more evenly throughout the seven-month season. However, in recent decades, the season has effectively been cut by more than half.

Because crabs mature faster in the more temperate waters of the Bay Area, the commercial Dungeness crab season in "District 10" — the portion of the California coast that extends roughly from Santa Cruz north to Point Arena, in southern Mendocino County — typically opens on November 15 each year, two weeks before the usual December 1 season opener for the northern coast, Oregon, and Washington.

In those two weeks of November, especially in years in which the Bay Area is projected to have a robust crab season, a slew of large boats, many of them based in northern ports, come down to the Bay Area and fish intensely, according to Larry Collins, president of the San Francisco Crab Boat Owners Association, which collectively bargains on behalf of San Francisco-based crab fishermen.