As you move aft, be sure to check the hatches on each and every compartment. These are items that you have to look at on an individual basis, throughout the boat, as one in the bow may be done properly while one in the stern may be a mess. Do they raise on gas–assisted struts? If so, make sure the thick end of the strut is mounted higher than the thinner arm, when the hatch is raised (this allows gravity–fed lubrication of the arm when it is in use). Look at the hinges. These should be through–bolted, and remember that longer piano–hinges will hold up better than short, small hinges, which can be stressed if someone leans on an open hatch. Also make sure hatches dog–down securely. Open the hatch all the way, to ensure it doesn't smack a gunwale or railing. And finally, if a hatch is on a fishbox or cooler, knock on it with your fist; a solid sound means it's a solid hatch but a hollow sound means it is cored, with a different material inside. Cored hatches are lighter, meaning they are easier to open and less apt to slam down.
LENNY RUDOWMore is better then it comes to rail stanchion fittings; three bolts make for a solid rail.
DOWN BELOW
Inside of the cabin, what you want to examine will vary considerably depending on the size of the boat and your expectations. As far as amenities go, it's an open book. But you can get an eyeball on some construction quality issues below decks, too.
The best place to do so is at the access points to the bilge. Here, again, you'll have to poke that noggin into places the builder never expected. Check for bulkhead fit and unfinished wood, which, in the bilge, is almost guaranteed to rot eventually. Examine pumps and pump switches to be sure they're solidly mounted with float switches running athwartships, not fore and aft (this prevents them from getting stuck in the on position). Look at wiring and plumbing lines. The most important thing to check is that they are all well loomed and supported. Also check where they run through bulkheads, to be sure they are chafe–protected. Make sure you take your flashlight and mirror into these areas. They'll help you look into corners and crevasses that would otherwise be out of view.
In the cockpit, once again the most telling details will be found below deck level. Make sure all bilge items of importance–pumps, seacocks, valves and batteries, among other things–are within reach. You'd be amazed how many builders bury these items in spots that only a contortionist could ever access. Remember that any through–hulls below the waterline should be fitted with seacocks that can be shut off via a ball valve, and that all hoses and fittings should have double hose clamps securing them. Stainless–steel clamps are a must – and here's where your magnet comes in handy. Many clamps are called stainless, but the screw and mechanisms in them are made with cheaper metal. Run your magnet across them, and if the magnet sticks to the metal, the clamps are cheap. Magnets won't grab real stainless. You can use this trick throughout the boat, to check suspect hardware and make sure it's real stainless.
LENNY RUDOWNote the gas-assist strut supporting the hatch, and the fact that it stops the hatch before it hits the gunwale. This is a top-notch arrangement.
The bilge is also the area where you can slap an eyeball on the stringers. These make up the backbone of the boat, so they're an important part of its structure. Usually stringers are either fiberglassed to the hull, or are set in a bed of Plexus or similar adhesive. In either case, look along the bottom edges to make sure there are no gaps or cracks between the stringer and the hull. In older boats, any indication of rot – older stringers were usually cored with wood – or stringer separation should scare you away. Massive repairs could be required to get the boat ship shape. The same goes for bulkheads where they meet the hull.
Another item to examine is the bilge pump outflow hose. What you want to see here is a loop in the hose, above the waterline, just before it hits the through–hull fitting. This is called an anti–siphon loop. If the through–hull dips below the water, this loop is what prevents the hose from back–filling the bilge with water.
While you are back here, you might as well check out the power system too, right? Maybe you feel comfortable poking around, but I recommend that a trained marine mechanic be called in for used vessels. Sure, most of us know enough to check the oil and make sure it's not milky (a sign of water intrusion), and look at the plugs and belts to be sure they're clean and in good shape, but the power plant is a complex beast on which you depend–so shell out the bucks for a pro, if you're serious about buying a boat.
The same goes for the structural integrity of older vessels, especially those made of wood, which really should be surveyed by a pro before purchase. On new boats, naturally, powerplant problems usually aren't much of a concern. There are a couple of performance details to check, but that will happen during your sea trial.
ON THE WATER
You're ready to leave the dock? Great–now shove that sales guy out of the way and take the wheel. You'll learn a lot more about the boat by operating it yourself. Is the wheel "sticky" or does it turn smoothly? Do you have to fight it at high speeds, or in sharp turns? Is the throttle tough to move, or easy? Operating the boat near the dock or ramp at slow speed is important, too, because some boats operate well at speed but are tough to handle at idle, or vise–versa.
