The short answer is “all you can afford.” The best investment is safety equipment that you have but never use; the worst investment is safety equipment you need but do not have!
First, there is the Coast Guard required equipment. Fire Extinguishers, Life Jackets, and Flares are the minimum. Don’t skimp here, especially on Life Jackets and Fire Extinguishers. On our Loop trip, we heard about two people who went overboard and died. We were involved with two people who fell into the water in marinas and needed rescue. Have more life jackets than you need, and keeping them close at hand is a good idea. When things go south (like when we hit the rock), everything happens fast, and going to look for life jackets, fire extinguishers, or hull patch kits takes precious seconds that you probably do not have.
Next, there are smoke and CO2 detectors. Again, this is not an area to skimp on. There are countless incidents where people have died onboard boats due to CO2 inhalation or fire. Fire, especially on a fiberglass boat, moves fast, produces toxic fumes, and can quickly cut off your only escape route.
CO2 is a silent, deadly killer. We have permanently installed CO2 detectors in our salon and both berths. We’ve had them go off and thought that they were false alarms, then realized that a boat blowing lots of exhaust had passed us with our window open, or we were in a lock and the boat upwind of us still had engines running. We suggest installing smoke and CO2 detectors in your engine compartments, all bedrooms, and enclosed areas like your lazaret. Consider linked detectors that all go off if one detects something so that you hear it all over the boat. As expensive as boats are, a couple hundred dollars for 6-8 detectors is not worth your life!
Another bit of advice is to ensure you are up-to-date on all your safety equipment. Make sure that you have checked your nav lights, that you have your placards, that your through-hulls for your overboard discharges are in the correct (off for blackwater) position and preferably labeled, and that your fire extinguishers have been inspected and labeled in the last 12 months. We were boarded and inspected by the Coast Guard. Our boat was all current, and it was a very friendly encounter. We got many “attaboys” for having things labeled and everything up to date. Many boaters who are inspected get fined. Some can exceed $500 per violation! We’ve talked to a few boaters who were escorted into port and held until they corrected some defective equipment. Keep your safety equipment up to date! It could save your life!
Before you leave for your Loop, contact your local Coast Guard Auxiliary; they will provide a free vessel safety check. While not quite as thorough as a full Coast Guard Vessel Inspection, it will give you a good basic check of your safety equipment. If you do get inspected by the regular Coast Guard, you will get a “yellow” copy of the inspection report. As long as you pass the inspection, this is referred to as the “Golden Ticket” because if you get stopped for an inspection again within a year, you can show them the prior report, and most times, you will get a pass!
Make a “Ditch Bag”. We have an official “Ditch Bag” from ACR, the EPIRB people. When we get underway, we put our wallets in it. We also keep a flashlight, our PLB, copies of our vessel documentation and insurance, our flare kit, and a couple of water bottles in it. It floats, and if we had to jump ship, we would have what we needed for a short-term survival/rescue situation. You don’t need an official Ditch Bag, a cheap dry bag that, when inflated, will float is more than enough. Again, it is all about saving precious seconds if disaster ever strikes.
All that said, you don’t need to go overboard (pardon the pun). We carry a PLB rather than a full EPIRB because we don’t go off-shore that often. We don’t have a life raft, but we carry some off-shore life jackets when we are out of sight of land. Use good judgment!