OBS Vehicle Inspection & Maintenance 2 — Questions and Answers
Question 1: When inspecting your boat's bilge pump, how should you verify it is functioning correctly before departure?
- Pour water into the bilge and activate the pump manually to confirm it evacuates water (Correct answer)
- Check that the pump switch lights up on the console
- Listen for the pump motor to hum when the ignition is on
- Inspect the pump impeller visually through the bilge access hatch
Correct answer: Pour water into the bilge and activate the pump manually to confirm it evacuates water
Testing the bilge pump by introducing water and operating it manually confirms the pump, hose, and discharge are all working before you leave the dock.
Question 2: Which of the following is the correct procedure for checking engine oil on an inboard gasoline engine before a trip?
- Check the dipstick while the engine is running to get an accurate reading
- Check the dipstick with the engine off on a level surface and wipe it before the final reading (Correct answer)
- Add oil until it overflows the fill tube, then check the level
- Only check oil after the engine reaches operating temperature
Correct answer: Check the dipstick with the engine off on a level surface and wipe it before the final reading
Oil must be checked with the engine off on a level surface; wiping the dipstick before reinserting ensures an accurate reading.
Question 3: What does a corroded battery terminal most directly risk on a boat?
- Overcharging the alternator and burning out the voltage regulator
- Increased electrical resistance causing poor starting or total electrical failure (Correct answer)
- Causing the battery to leak acid into the bilge rapidly
- Triggering the automatic bilge pump to run continuously
Correct answer: Increased electrical resistance causing poor starting or total electrical failure
Corrosion adds resistance to the circuit, reducing current flow and making it difficult or impossible to start the engine or power navigation lights.
Question 4: During a pre-departure hull inspection, you notice a soft or spongy area on a fiberglass deck. What does this most likely indicate?
- Normal flexing in the fiberglass laminate under foot pressure
- Water intrusion and delamination of the core material beneath the deck skin (Correct answer)
- Air pockets left over from the original fiberglass layup
- The non-skid surface coating is wearing thin
Correct answer: Water intrusion and delamination of the core material beneath the deck skin
Soft spots in fiberglass decks typically indicate water has entered and saturated or rotted the foam or wood core, causing delamination.
Question 5: How often should you inspect your boat's steering cable or hydraulic steering system for proper operation?
- Only after the boat has been stored over winter
- At the start of every boating season and periodically throughout the season (Correct answer)
- Every five years as recommended by the Coast Guard
- Only when the steering feels noticeably stiff or pulls to one side
Correct answer: At the start of every boating season and periodically throughout the season
Steering systems should be inspected at the beginning of each season and checked periodically because a failure at speed can be catastrophic.
Question 6: What is the primary purpose of a zincs (sacrificial anode) attached to a boat's outdrive or propeller shaft?
- To add weight that stabilizes the boat's trim at high speed
- To prevent galvanic corrosion from destroying metal underwater components (Correct answer)
- To improve propeller efficiency by reducing water turbulence
- To ground the boat's electrical system to prevent static buildup
Correct answer: To prevent galvanic corrosion from destroying metal underwater components
Sacrificial anodes made of zinc (or aluminum or magnesium) corrode preferentially, protecting more valuable metal components from galvanic corrosion in water.
Question 7: When inspecting your vessel's fire extinguisher before departure, what three things must you verify?
- Brand name, purchase date, and storage location
- Proper classification, charge level, and absence of damage or corrosion (Correct answer)
- Pin is in place, hose is attached, and label is readable
- Pressure gauge reads red, nozzle is clean, and pin is pulled
Correct answer: Proper classification, charge level, and absence of damage or corrosion
A serviceable marine fire extinguisher must be the correct type for the hazard, fully charged (gauge in green), and free of physical damage or corrosion that could impair use.
OBS Vehicle Inspection & Maintenance 2
When inspecting your boat's bilge pump, how should you verify it is functioning correctly before departure?