Sea Trials

If you can’t afford a marine surveyor, you need to rely on yourself to perform the sea trial. By the time you get to this stage of the buying process, you should have a pretty good idea what kind of boat it is you’re considering. You just need to confirm your choice—or decide not to buy. But what does a marine surveyor look for? There’s a lot to look for, and it begins before the boat even goes in the water.

To get you started, follow these steps outlined in our basic sea trial checklist.

Sea Trial Checklist

  • Perform a thorough inspection while the boat is on the trailer.
  • Check the hardware and trim. Is everything tight?
  • Are the stowage compartments dry or do they smell moldy and damp?
  • Look under the engine. Inspect nooks and crannies you can’t normally see.
  • Use all your senses. Look. Sniff. Touch. Listen.
  • Do a cold start. Listen for knock on startup and continued valve clatter. A little ticking initially on cold startup is not uncommon, but continued ticking is.
  • Take it to top speed and see if it does anything odd or unsafe.
  • Find the cruising speed. Is it fast enough for your needs?
  • Test its handling by driving the boat through an imaginary slalom test. It should transition from turn to turn as smoothly as your inputs. No snapping or hooking.
  • Open the hatch and have another look around.
sea trial checklist

Sea trials are always exciting, but don’t let emotion rule you; and if you’re new to the game take along an experienced friend and/or your marine surveyor.

Now, let’s dive back into the details of each step…

When the boat is on the trailer, walk around it thumping the sides of the boat with the bottom of your fist. The hull should ring with a solid whump and it should feel firm under your fist. This is particularly important in the transom area, where water intrusion typically appears first.

Look at the condition of the underwater gear. Is the skeg still nicely painted? Is the leading edge still straight and true or is it pocked and jagged from hitting rocks or sandbars? If it is damaged, keep its condition in mind when you shift the boat in and out of gear during the sea trial.

Look at the condition of the bottom of the boat, particularly the keel and the chines. A boat that’s been run around often will have scratches near the keel. A boat that’s been Forrest-Gumped onto its trailer often will show chips around the keel, chines, hullsides and maybe the prow near where the bow is.

While you’re still on dry land, get on board and see and touch everything. Wiggle the grab rails to see if they’re loose. Sit in the pedestal seats to see if they’re still mounted firmly to the sole. Open up all the stowage compartments to be sure all the hinges are still solid. Also, use all your senses.

For example, give those stowage compartments a sniff to check for mold or mildew. Also smell under the engine hatch. You likely will smell gasoline to a certain degree, but anything overpowering could indicate a fuel leak. Get down on your hands and knees and look in places where you wouldn’t normally look. You may discover missing hardware or frayed carpeting or upholstery.

Now for the sea trial, the most important part. The boat should be stone cold when you fire it up for the first time. If the engine’s rotating assembly is going to make any funny noises or exhibit any loose clearances, it will be when it’s cold. Open the hatch so you can hear everything better. Does the starter engage smoothly and quietly? Does the engine rattle or knock when you start it? It should run with little more than a thrum of vibration and the hiss from the flame arrestor atop the engine.

The same goes for outboard-powered boats. Pull the cover off the engine before cold-starting it. Outboard covers have sound insulation on them to keep the interior of the boat quiet, which is great, but they can mask noises you need to hear during a sea trial.

Be sure to check all the stowage compartments for mold or mildew—and don’t forget to look under the engine hatch or pull off the cowling if the boat is outboard powered.

As you back out, notice how the shifter works. Does it engage forward and reverse when the shifter is moved to the detents? Is there any binding or sticking in the shift cables? Not all signs of trouble will be deal-breakers, but paying attention to these details also can help you develop your punch list if you decide to buy it.

When you advance the throttle, notice how difficult or easy it is for the boat to get on plane. Some boats plane out better than others, so now is the time to see if it’s something you can live with every boating day. Once you’re up and cruising, take it top speed. The boat should do that and hold that speed with no trouble. If you’re satisfied with the result, bring it back down to cruising speed—usually 3,500 rpm is a good rule of thumb.

At that speed—in an area where it’s safe to do so—take the boat into right and left turns. Do slalom maneuvers then full circle turns. The boat should hold its line without hooking, washing out or blowing out the prop. If the boat has a stepped bottom, don’t trim it down to do these tests. While you’re doing this listen for cautionary squeaks and rattles.

If you’re satisfied, cruise it back the dock the way you normally would. Once you get back to an idle zone, open the engine hatch and do another full sensory check. Many times an engine that has been warmed to operating temperature will act different from one that is still cold.

Will this procedure keep you from buying a lemon? There is a chance any used boat you buy will need some work not long after you buy it. Using the techniques listed above, you learn a lot about any boat this way. The method not only can expose mechanical foibles and idiosyncrasies, yes, but it also can highlight—perhaps most importantly—whether you like it enough to buy it.

For more information, be sure to read What to Look For on a Sea Trial.