Spring Commissioning Checklist

Spring Boat Commissioning Checklist

Getting your boat ready after winter storage involves more than installing the drain plugs and turning the key. This spring commissioning checklist will help you inspect the boat, start the engine safely, and identify potential problems before leaving the dock.

Back in another life, BAM Marine owned a marina in Chicago. We developed these procedures while preparing boats for another season on the water.

Important: This is a general checklist—not a replacement for the procedures in your engine and boat manuals. Always keep hands, clothing, tools, and equipment away from belts, pulleys, propellers, and other moving or hot components.

Before Starting the Engine

Complete these checks before turning the key:

  • Keep a usable marine fire extinguisher nearby.
  • Install all drain plugs. Check the hull, bilge, engine, manifolds, coolers, and any other locations that may have been drained during winterization.
  • Inspect the battery. Make sure it is charged, clean and protect the terminals, and check the electrolyte level if applicable.
  • Check the engine oil level and condition. Ideally, the engine oil and filter were changed during fall winterization.
  • Inspect belts and hoses for cracks, looseness, deterioration, or missing clamps.
  • Check the coolant level if the engine has closed cooling, also known as freshwater cooling.
  • Inspect the bilge for fuel, oil, coolant, or unexpected water before starting the engine.
  • Provide the correct water supply if the boat is out of the water.
Never run the engine without cooling water. Even a brief dry start can damage the seawater pump impeller and cause the engine or exhaust components to overheat.

Ventilate the Engine Compartment

On gasoline-powered sterndrive and inboard boats, make sure the bilge blower operates properly. Confirm that air is moving through the exterior vent—the blower hose may have come loose during storage.

Run the blower for at least five minutes before starting the engine and any time fuel vapors may be present. If you smell gasoline, do not start the engine. Shut off electrical equipment and locate the source of the fumes.

Start the Engine and Check Immediately

  1. Start the engine without revving it. A speed slightly above idle may be appropriate when specified by the engine manufacturer.
  2. Check the gauges immediately. Confirm that the engine has oil pressure and no warning alarms are active.
  3. Verify cooling-water flow. Watch for proper water circulation and carefully monitor the exhaust elbows or manifolds for abnormal heat. An infrared thermometer is safer and more accurate than touching hot engine components.
  4. Do not rely only on the dashboard temperature gauge. Exhaust components can overheat before the engine temperature gauge shows a serious problem. If cooling water is not circulating or the exhaust begins heating rapidly, shut the engine off and determine why.
  5. Look for leaks. Use a flashlight to inspect the engine compartment for fuel, water, coolant, or oil leaks. Pay particular attention to the oil filter, drain hoses, cooling-system connections, and anything disturbed during winterization.
  6. Recheck the engine oil. If the oil becomes milky or cloudy, water may be entering the crankcase. Shut the engine off and investigate before continuing.
  7. Check the gauges again as the engine warms. Watch the oil pressure and temperature, and verify that the voltmeter indicates the charging system is operating.
BAM Tip: Stay with the engine during the initial startup. The first few minutes are when you are most likely to discover a loose hose, forgotten drain plug, cooling-water problem, or leak left over from winterization.

Before Leaving the Dock

Once the engine is operating normally, inspect the rest of the boat:

  • Test the automatic and manual operation of all bilge pumps.
  • Inspect bilge pump hoses and discharge fittings.
  • Test the running, navigation, anchor, and courtesy lights.
  • Confirm that the horn and other required safety equipment are operational.
  • Turn the steering from side to side and verify full, smooth movement.
  • Check the throttle and shift controls for proper operation.
  • Inspect the fuel system for leaks or deteriorated hoses.
  • Verify that safety gear, dock lines, and life jackets are aboard.

Perform any shifting test only when the boat is safely secured and the propeller area is completely clear.

Need Maintenance Parts?

Mercury and MerCruiser service kits package many of the common maintenance items for a specific service interval into one convenient kit.

Browse Mercury and MerCruiser maintenance kits →

If you are unsure which parts or service kit fit your engine, use your serial number to locate the correct parts diagrams.

Look up parts and maintenance kits by engine →

Once everything checks out, it is time to enjoy another boating season!