- Please keep these annotations SPOILER-FREE by not revealing information from later pages in the novel.
Page numbers refer to editions with 369 pages, where the story begins on page 1. Not sure if there are other editions with variant pagination. Please let us know otherwise.
Doc called Sancho next morning
Morning, Saturday, March 28, 1970, the fifth day of the narrative.
Ginger . . . Skipper . . . Gilligan . . . Thurston Howell III . . . Lovey
All characters from the TV show Gilligan's Island. See below for more references to this iconic show.
The largest city and capital of the US Virgina Islands.
Like new debt... from institutions in places like South Dakota that you send away for by filling out the back of match cover
Sauncho's quote here echoes almost exactly Zoyd's thoughts in Vineland in regard to Isaiah Two Four's business proposition: "expecting some address in a distant state, obtained from a matchbook cover." (p. 19, Vineland)
An error. Should be "Joseph Arnould", who wrote Law of Marine Insurance (1848).
There were two men (father and son) named Theopilus Parsons in the nineteenth century. This reference is to the younger one, who published A Treatise on the Law of Marine Insurance and General Average in 1868.
Another reference to Gilligan's Island. "L'il buddy" was the captain's nickname for Gilligan.
Also, Hector calls Zoyd this in Vineland, see p. 26. The contraction is spelled li'l in Vineland but l'il in Inherent Vice.
A perhaps obvious pun on Il Trovatore, the Verdi opera.
This name is likely derived from a 1910 noir-ish murder-mystery novel Paternoster Ruby by Charles Edmonds Walk. Alexander Stilwell Burke and Stodger, a plain-clothes cop, are two main characters. Google Books Perhaps Pynchon's slyly recycling here some unused stuff from his vast research for Against the Day? A excerpt from Walk's novel:
- "Nasty case," Stodger was imparting, in queer staccato sentences. "Shouldn't have much difficulty, though; responsibility lies between two men. Here all last night. Nobody else. Callahan and O'Brien holdin' 'em. One 's Page's private secretary; fellow named Burke Alexander Stilwell Burke. Peach of a monicker, ain't it? Has all three sections on his cards.
- Suddenly she snuggled closer and clasped her hands tightly upon my shoulder. Her hair teased my cheek, and the delicate perfume of it made me light-headed. Twisting her pretty head sideways, she flashed an arch look at me from under her lashes, then glanced quickly away again. Blue eyes and long dark lashes are a potently disturbing combination.
- "Well," she sighed, "the Page case may have cost you a fortune, but it gave you me. And I for one am very content and happy, Mr. Swift."
a three-hour tour
Yet another reference to Gilligan's Island. This is a quote from the theme song.
Marcus Welby, M.D.
Hour long medical drama that aired on ABC from '69-'76. Took place in Santa Monica and ranked first in Nielsens for the year 1970.
what Cheech and Chong might call matzo-ball jones?
Punned reference to "Basketball Jones", song on Cheech and Chong "Los Cochinos" album with release date 1973.
Raymond Chandler's famous detective, featured in Chandler's many novels set in LA, including The Big Sleep (1939; his first appearance), Farewell My Lovely, and The Long Goodbye.  There are many important parallels between Pynchon's Doc and Chandler's Marlowe, especially his world-weariness, his fondness for certain drugs of choice, and a penchant for cracking wise and getting beaten up and worse. (John D. MacDonald's fictional detective Travis McGee is also an important predecessor; see below). Of all Chandler's fiction, Farewell My Lovely (1940), which many think is Chandler's best, may be most relevant for the plot and themes of Inherent Vice. For instance, in that novel Marlowe stays in a hotel in Venice Beach before going out to Laird Brunette's offshore gambling boat, the Montecino. Farewell My Lovely also has "rehab" centers that serve as a front for torture and murder; characters with hidden identities; an impossibly convoluted plot; and a literary style that features striking metaphors, similes, and literary allusions. Marlowe is, like Doc, a dark mixture of cynicism, doggedness, and indifference--yet his goodness and inherent virtues can't be killed. To trace the parallels with Chandler's Marlowe, though, is to see how fully Pynchon has transformed and deepened the generic conventions of 1930s and '40s detective fiction (and film noir inspired by it) even as he pays homage to these.
Dashiell Hammett's detective in The Maltese Falcon (1930) and other crime fiction; in John Huston's famous film based on the novel, he's played by Humphrey Bogart. 
Johnny Staccato is a private detective series which ran for twenty-seven episodes on NBC from 1959-1960. Title character Johnny Staccato, played by John Cassavetes (1929-1989), is a jazz pianist/private detective. 
Krazy Kat was a popular comic strip that ran in newspapers from 1913 to 1944. Ignatz and Offisa Pupp are characters.
Detective in the TV show Hawaii Five-0, important to both Vineland and Inherent Vice.
"Why not get a houseboat up in the Sacramento Delta--smoke, drink, fish, fuck..."
It's tough not to see this as a nod to Doc's brother shamus Travis McGee, the creation of Florida writer John D. MacDonald. McGee lives on a houseboat, taking his "retirement in installments," drinking, lounging on Florida beaches, meeting and inevitably helping beautiful women out of troubles that almost always involve a sinister land broker or two. Along the way Trav usually ends up pontificating about rapacious land developers, the increasingly artificial and isolated American lifestyle, and people's loss of connection with the natural world. 
Surnise was on the way
Early morning, Sunday, March 29, 1970, the sixth day of the narrative, and Easter Sunday.
[T]he engine sounds were not passing across the sky where they should have . . .
An apparent allusion to the opening line of Gravity's Rainbow. As a consequence of this, "everybody's dreams got disarranged," which also seems to be happening on GR's first page
This is a surfing/skateboarding term for someone who rides left-footed. So-called regular foot riders keep their left foot at the front of the board, but goofyfoot riders put their right foot at the front. More here.
Doc, also up early
Early morning, Sunday, March 29, 1970, the sixth day of the narrative.
a surfer or two who'd found and ridden other breaks [...] unphotographed and unrecorded
Even though Pynchon's reference to Mavericks would seem an anachronism, as no one other than a couple surfers had even tried Mavericks until Jeff Clark began riding the gigantic break in 1975, alone, until 1990 when he convinced some other surfers to check it out, this description would seem to fit Jeff Clark perfectly, discovering and surfing, alone, some of the largest waves on the planet. Jeff Clark Wikipedia entry... Pynchon himself, as we all know, likes to remain unphotographed.
in the slow seep of dawn
Early morning, Sunday, March 29, 1970, the sixth day of the narrative.
They were outside on the beach, it was nighttime
Night, Sunday, March 29, 1970, the sixth day of the narrative.