Suck it up
Automatic bilge pumps must have a manual override and an indicator light to show they're running. The discharge hose must have a vent above the waterline so that water doesn't siphon back into the hull.
Off is on
Automatic bilge pumps should function when the master battery switch is turned off. To test, reach into the bilge and lift the float switch. The pump should run and indicator light come on.
To see if your genset is big enough, turn it on and crank up the air conditioning and other loads for 30 minutes. And remember, bigger isn't always better, as gensets are happier and more efficient under load.
An easy way for a builder to save money is to have the genset share the main engine's exhaust, something that should be avoided. Separate exhausts ensure less buildup of carbon, which can otherwise shorten the genset's life.
Ensure that the air conditioner can draw down cabin temperature by at least 20 degrees. Ditto for the reverse-cycle heat function.
Fill any and all sinks, basins, shower sumps, livewells, and so on to see if the pumps can evacuate the water. Look to see how much water is left standing after the level drops below the drain intake.
Turn on the battery charger. Using a multimeter set to accommodate 12-VDC, check the voltage at each battery. Dead or weak batteries will show a higher charging voltage.
The new black
Look for corrosion-protected terminals, booted (covered) positive battery and starter motor terminals, wires supported at least every 1'6", and yellow (which now takes the place of black) 12-volt ground wires.
Turn the main battery switch to On. Does all DC gear work? Good. Now turn the battery switch to Off. Everything should go off except for the automatic bilge pumps. Nothing else should bypass the master switch and be wired directly to the battery.
All metal fittings likely to come into contact with the water should have a green wire that connects to a single grounding point. This minimizes the possibility of corrosion and keeps swimmers safe from shocks.
Surveyors use a silver/silver chloride electrode ($120; www.boatzincs.com) connected to one lead of a multimeter and hung overboard. They then touch every wet fitting on the boat with the other lead to check for dangerous and corrosion-causing current leaks. You should do the same.
Crawl under or inside stowage and cabinet spaces to see if the cabinets are installed securely. Look for loose screws and sloppy gluing or fiberglass work.
Microwaves, refrigerators, freezers, and dishwashers can become projectiles in rough seas. Look for bolted and backed mounts. Then look to see whether the refrigerator and freezer doors have hinges on the stern side. If either does, the door is likely to come open while getting on plane.
If the cooktop has a cover that slides over the burners, make sure it has a cutoff switch so the lid doesn't burn. The sink drain must have a P-trap to prevent back siphoning of water -- this may also help prevent exhaust fumes from the engine or genset getting into the cabin.
If the head has an overboard discharge feature, check to make sure you can reach the Y-valve in order to disable it while you're in port -- you don't want anything emptying where it shouldn't. Can you get to the shower sump to clean it without unscrewing parts of the boat?