I think of this as an adjunct to my book "Keeping a Cruising Book for Peanuts," although certainly there is some overlap. I've tested a lot of stuff. Many of these items were mentioned in some prior post--use the search function to find more information.
While you're at it, subscribe to Practical Sailor Magazine. The product descriptions are better, there are comparisons and options, and the test methods are explained. They research stuff I avoid, like electronics. One good find--or bad purchase avoided--and it'll be the smartest $39.94 you'll ever spend.
Pointed aft, the Borra helps move the AC around, point towards the heater (right), it spread the heat. Very quiet.
6. Cabin Fans. The Caframo Borra is my new favorite, after I had three Hella Turbos fail in a two week period, one with flames and two with smoke. The four was moved to the helm position, where I figure I can keep an eye on it. The Borra got a "best" rating from Practical Sailor, it is quieter than the turbo, moves more air, and the direction is easier and the setting more secure. They have done a superior job of both cooling and distributing heat and cold. In nine years there have been no glitches (the Turbos failed at 11 years, so I guess I should cross my fingers).
[A reader, below, reported trouble with the switch within a few years. The PS test in 2009 noted one failure. My understanding is that the switch was redesigned, but perhaps problems persist.]
7. Home Depot Caulk that Works. Locktite PL S40 is a polyurethane caulk with physical characteristics and durability that match 3M 4200 for one third the price. Like all polyurethane caulks, humidity is the curing agent. Additionally, it is messy to work with, so always mask the work area, wipe thin with a finger, and then peal the tape before it skins over. Available in Black (PL S30) and other colors.
A strong jackline anchor with no new holes. The webbing protects the lashing from the sun. There is a backing plate on the underside.
8. Stainless Steel Climbing Bolt Hangers. My favorite hard point for attaching deck cargo, anchoring jacklines, and clipping safety tethers. They are well-tested, clip carabiners smoothly, and best of all, require only a single mounting bolt. This means I can often mount them by simply removing an existing mounting bolt and inserting a 3/8-inch bolt in its place (required to meet rated strength). Metolious is one of my favorite brands, but any climbing gear with a UIAA stamp is safe. Like wire gate climbing biners, the secret of low price is mass production and simple, rugged design.
9. Star Brite Cleaner and Degreaser. I'm usually the first one to say "formulate your own" or buy something from Home Depot, but this one has saved my bacon a few times, powering black oil and grease out of porous gelcoat. I'm almost out and need to buy more.
These really save your ribs when you take a long stumble.
10. Dynamic Climbing rope, 8mm. Perfect for shock-absorbing traveler control lines (mine are ~ 55 feet), shock-absorbing safety tethers (2 x 11 feet), and shock absorbing bridles/snubbers (2 x 38 feet, for boats under 36 feet) . That's only 150 feet, or just 79 feet if you skip the bridle. The Beal Rando (UIAA 1/2 rope) is available as a 30 meter glacier rope, or you can buy it by-the-foot from Mountain Equipment Coop. I did all three, using a lightly used 150-foot ice climbing rope I had just retired.