NOTE: I have adapted the following notes into a much longer essay on Wikipedia; see the Wikipedia article here.
The novel The Boats of the "Glen Carrig" starts in the middle. We know almost nothing about what happened to the "good ship" Glen Carrig. The subtitle mentions that it sank after striking a rock. We know nothing about the fate of the captain or how many people were lost. The lifeboats have no names. The title and subtitle seem to indicate that the boats are the subjects of the novel, although this conceit is not continued in the text.
There is a narrator. We are not told his name in the text, althouth the subtitle indicates the story is told by "John Winterstraw, Gent." The "Gent." is a hint about the narrator -- he is a man of status. There is a subtle class consciousness that plays itself out in the text, showing up especially in the end of the story, which I won't give away just yet.
His son, James Winterstraw, presumably doesn't get to use the title "Gent.," at least not yet, although in what may be the only deliberate humor in the book, he does give himself a little praise for writing down his father's story "very properly and legibly!"
Interestingly, the narrator is not really the hero of the story -- that honor goes to the bo'sun, who frequently behaves heroically, showing extremes of endurance, ingenuity, and bravery. The narrator greatly admires the bo'sun, although from a social distance. He portrays himself as more quick-witted than most of the crew, and he mentions with pride that his help is specifically requested by the bo'sun. The narrator does get some slight comeuppance, though, when his plan to use a giant bow to shoot a rope from the island to the weed-trapped brig fails [see end note 1], and another crew member comes up with the idea to use a kite instead.
The text is written, as I have mentioned before, in an archaic style. Reading the novel now, you can imagine that we are looking through a spyglass backwards through two lenses: first, it has been about 100 years since Hodgson wrote this novel. And second, Hodgson himself was writing about fictional events that he imagined had happened at least 150 years earlier.
Here are annotations for a few of the archaic terms used in The Boats of the Glen Carrig. I'm not going to go into details about the rigging of sailing ships -- that is only likely to reveal my profound ignorance on the subject, and the exact nature of different sails is not critical to understanding the story. But I think a few terms are worth discussing, and might help the reader see through that spyglass a little more clearly.
Batten: in the context of boat repair, a thin strip of wood.
Biscuit: "ship's biscuit" or "hardtack" is a dense, unleavened bread designed for long storage. They would be very dry, and probably not very easy to chew without soaking in some kind of liquid. Accounts of the flavor vary -- if you were starving to death, ship's biscuit probably tasted pretty good!
Bo'sun: slang form of "boatswain." A sailor in charge of the deck crew and lifeboats. We aren't told, but it seems likely that the captain of the Glen Carrig "went down with the ship" and thus the bo'sun is in charge of the suriving crew and passengers in the boats.
Breaker: in context, a small water cask. Finding fresh water is one of the crew's main concerns.
Brig: a two-masted sailing ship.
Bulkhead: a wall within a ship. Hodgson describes the bulkheads of the ship in the creek as having a "rubbed" appearance after the assault by the strange unnamed creature.
Colza oil: a vegetable oil pressed from a seed of the rutabaga. It is used in oil lamps and for lubricating machinery.
Cut-and-Thrust: the term refers in general to fighting with knives. I'm not entirely clear on just what kind of knife Hodgson was referring to, but it may have been a rapier, a slender sword with a sharp point. I think Hodgson gave the narrator a rapier, a fancy sword which would have required training, as one of the signs that he was of a higher social class than the sailors.
Cutlass: a short, thick sword with a sharp edge. A cutlass required little training to use effectively and, being short and heavy, could be used for fighting in confined spaces such as on board a ship.
Devil-fish: this word has been used to describe several different sea creatures, but in context it seems that Hodgson was referring to a monstrously large octopus. In several places Hodgson describes its movements as "flickering," which makes sound like it is moving with unnatural speed.
Dip: a candle. Hodgson refers to "tallow dips" made from fat.
Fathom: a unit of length, about 1.8 meters or about six feet. The term is now usually used only for water depth, but Hodgson uses it for distance as well.
Flake: In this context, an archaic term for coiling rope.
Fo'cas'le: the forecastle. The forward (Hodgson uses the slang spelling "forrard") part of the ship with the crew's quarters; on ancient vessels these resembled castles.
Frap: A "frappe" (with or without an accent on the e) is a frozen drink or milkshake. The word "frap" seems to be an archaic nautical term roughly synonymous, in this context, with "wrap." Hodgson uses this term to describe the way the strings of the stacked bows are bound together so that the bows can be fired as one.
Futtock: A curved piece of wood that forms the rib of a boat. It seems to have nothing at all to do with a futtock-shroud. It is not a naughty word.
Futtock-shroud: An iron bar used to stabilize a "top," or platform on the top of a lower mast. A "futtock-shroud" is not really a "futtock" nor is it a "shroud." Discuss. Also, a "shroud" is not a shroud, but a collection of rope lines. Confused yet?
Grain: in a list of miscellaneous items removed from the boat, Hodgson mentions "a three-pronged grain without the shaft." I was not immediately able to find a definition for "grain" that makes sense in this context, but I suspect he is referring to some kind of iron grappling hook. If you've got a better idea, please send me a note.
Gunwale: pronunced (and sometimes written) "gunnel," the top edge of the side of a boat.
Jorum: a drinking vessel, or the quantity that it contained. Hodgson uses the term to refer to a quantity of rum given to Job for medicinal purposes -- presumably a large dose.
Keel: the main structural member, running the length of the boat from bow to stern. It is very fortunate that the boat's keel is not damaged by the devil-fish attack, but only some of the boards adjacent to it.
Larboard: the port (left) side of a boat, to someone facing the front (bow).
Lazarette: This is a small compartment below the deck of a ship, used for storage. Hodgson uses this term in many of his sea stories.
Loom: part of the shaft of an oar. Job is injured while struck by the "loom" of an oar, when a devil-fish attacks the boat.
Mantilla: a light lace scarf worn over the head and shoulders. Hodgson uses this word in his dedicatory poem, "Madre Mia," as a metaphor for the effect of age on his mother's appearance.
Oakum: This is loose hemp fiber, hand-picked out of old rope (an extremely labor-intensive process). The loose fiber could then be mixed with pine tar and used as caulking, was stuffed into cracks in wooden boats with specialized tools. The work of "picking oakum" from rope was done in work-houses, prisons, and asylums.
Ordinary Seaman: a sailor with between one and two years of experience at sea. An ordinary seaman would have been expected to do a wide variety of labor-intensive jobs on board a ship.
Sea-anchor: a sea anchor does not anchor a boat to the bottom of the sea, but instead is designed to drag in the current, and helps to stabilize the boat during bad weather and keep the bow pointed into the waves, which minimizes the risk that the boat will be overturned.
Scuttle: a hatchway in the deck, side, or bottom of a ship, with a cover. Hodgson refers to the "leaf" of the scuttle (the covering).
Sennit: A form of braided cord; Hodgson describes "three-yarn sennit" made from old hemp rope found on the island.
Starboard: the right side of a boat, to someone facing the front (bow).
Step (verb): Hodgson describes the crew "stepping" the mast after the storm. This means to literally re-attach the mast, which they had removed and used along with the oars as a sea-anchor.
Stern: the rear of a boat.
Thole: an oarlock. A holder that holds an oar in place for rowing.
Thwart: a seat extending across the inside bottom of a boat. Hodgson several times describes the men as standing on a thwart: they are standing up on the seats to see clearly over the gunwales.
Tithe: in chapter 14 the narrator says that they did not "discover more than the merest tithe of the mysteries which that great continent of weed holds in its silence." Traditionally this term meant the donation of a tenth of one's income to the church; in context it means "a small fraction."
Whaleback: the term refers to a type of boat designed to shed water, but in context Hodgson seems to be referring to some kind of rib-like structure that could be raised up and covered with canvas to protect the lifeboats from rain and water.
 The whole notion of firing a rope to a ship and rescuing people aboard by using a chair sliding along the rope may seem unrealistic, but I assure you it is quite possible. The Michigan coast guard at Sleeping Bear Point Lifesaving Station was equipped with a "Breeches Buoy," or a sliding chair, to rescue people from boats within three or four hundred yards from shore, although a "Lyle Gun" instead of a bow was used to fire a projectile carrying the first line, which was carefully pre-coiled in a basket to avoid fouling.