The All-Important Spring Sea Trial

Great morning run.JPG

Most boat owners can’t wait to get batteries charged up, provision the galley, spruce up the interior, and put all the cruising stuff back aboard. For those up north, it is time to ditch the shrink wrap. A spring wash, wax, and detailing gets her looking good, and a casual inspection of the ship’s systems highlights that everything still works after a few months of off-season rest.

When the boat is launched, the season begins. But wait! Not so fast. Before your cruising begins, whether locally, beginning a Loop, or some other adventure planned over the winter months, there is a step that every boat owner should take. And it matters not whether it is a traditional trawler, a fast cruising motorboat, or a day cruiser like I have now.

And that is to perform a thorough sea trial.

What I mean by this is to get the boat underway, and check all systems, lights, electronics, galley and comfort systems. Does the fresh water pump under the galley sink still work, or has a loose clamp caused an air leak? Do the windshield wipers work? How about the horn? Lots of things to check on a cruising boat. And for whatever reason, some things just stop working from sitting idle for a few months.

And for a trawler or cruising motorboat, pay particular attention to the engines and generator.

Part of every sea trial also should include bringing the engines up to full throttle for at least five minutes. It won’t damage your engines. And if anything is on the verge of breaking, falling off, leaking, or disintegrating, let it happen now. Near home.   

Trust me, I’ve been down this road.

We took a test drive while looking for a boat one year. The broker had us aboard an owner’s boat to see if this style boat fit us. Friends came along as we motored along on calm water, walking around the boat to get the feel of a faster cruising boat. My friend wanted to drive and as he took over the helm, he asked the broker if he could run her up to wide open throttle (WOT) to see what she could do.

He pushed the throttle forward and we shot off like a thoroughbred. Not used to such power displayed in calm conditions, we were all smiles until shortly after an engine alarm sounded and the engine went into “survival mode.” We shut it down.

A rusted hose clamp had let go on the intake hose to the engine’s raw water pump, and without water it was beginning to overheat. After a few minutes to let the steam and heat dissipate, the broker was able to re-attach the hose with a new hose clamp, and we were soon on our way, while the bilge pump emptied the water that collected underneath us. The vibration of the WOT engine caused the failing clamp to break apart.

Another experience occurred on Blue Angel, our Hunt Harrier. One summer morning I was returning home from a run into Spa Creek in downtown Annapolis and decided to see if the boat would still hit 42 knots as she had on her sea trial in Buzzards Bay when we bought her the previous year. Alone on Whitehall Bay, I throttled up and we cut around the buoys coming back into Whitehall Creek like a hot knife through butter. Lovely.

Until the smell of melting rubber and smoke came out of the engine space. Running the engine at full power caused a loose hose clamp to let a different hose come loose, this one between the heat exchanger outlet into the exhaust system. Water poured from the heat exchanger into the bilge instead of cooling the hot exhaust gases. No alarm sounded, and no “survival mode” took over, as the heat exchanger cooled the engine just fine, but the exhaust system hoses began melting. It was an expensive repair.

You can see smoke from the melting exhaust hoses, and the blown crossover hose. All hoses had to be replaced. The engine was fine.

You can see smoke from the melting exhaust hoses, and the blown crossover hose. All hoses had to be replaced. The engine was fine.


The point obviously is that at the start of the season, running your freshly-launched boat up to full power is an ideal way to check for such issues while close to home and familiar marine services.

While running at full power, carefully examine all gauges and note temperatures. If filters are on the verge of clogging, this will happen now, as will any pumps or recently serviced fittings. If an O-ring on your fuel filters didn’t seat properly when you changed the filter element during winterization, the air leak will cause a problem now. If you had prop work done over the winter, check to see if you can reach maximum rpm, indicating proper pitch. If a service tech adjusted the engine valves last fall, did he get them all right to spec? Funny noises should be listened to.

If the engines don’t appear to reach full throttle, according to your tachometer(s), be aware these gauges may be at fault, especially older mechanical tachometers, which are prone to inaccuracies. These can later be checked against readings from a handheld tachometer.

When you return from the sea trial, go back in the engine space. Are there any odd smells? Can you see any pools of oil, diesel, or water? Does everything seem in order?

Did all the hoses stay on?

If you never run your boat at full power, but always loaf along in the comfort zone of the trawler lifestyle, what happens if conditions change and you are forced to boogie out of harm’s way with an approaching thunderstorm? What would happen if you pushed forward the throttles only to find the engines shut down because an aging fuel hose finally cracked open or cooling hose came off or burst? Or in the case a new yacht I never wrote about, the ground wire came off the control box for the electronic engine controls and we only stopped the boat when it crashed into a dock, causing expensive damage to the boat but thankfully no injuries. There are many scenarios I could mention, and they exponentially increase when we talk about boats that are 30+ years old.

The value of the spring sea trial is a confidence-building exercise that can identify problems, and every prudent cruiser should perform this annual spring event. It makes for a much more enjoyable season of carefree cruising.

I now make sure Blue Angel’s hose clamps are tight every spring.