SAMS Hull and Machinery Surveyors 3 — Questions and Answers
Question 1: A surveyor finds that a vessel's propeller shaft has a measured runout of 0.018 inches at mid-span. What is the most likely consequence if the vessel operates without correction?
- Increased fuel consumption only
- Accelerated cutlass bearing wear and vibration (Correct answer)
- Reduced propeller thrust by 10–15%
- Overheating of the stuffing box gland
Correct answer: Accelerated cutlass bearing wear and vibration
Shaft runout exceeding acceptable limits causes cyclic loading on the cutlass bearing and generates vibration that accelerates wear throughout the stern gear assembly.
Question 2: When surveying a steel vessel, which corrosion pattern in the bilge area most strongly suggests accelerated galvanic activity rather than general atmospheric corrosion?
- Uniform red rust over large flat surfaces
- Pitting concentrated around bronze through-hull fittings (Correct answer)
- Orange discoloration of welds only
- Scale formation on frames above the waterline
Correct answer: Pitting concentrated around bronze through-hull fittings
Galvanic cells form preferentially between dissimilar metals in the presence of an electrolyte; pitting near bronze fittings in the bilge indicates the steel hull is acting as the anode.
Question 3: Under NFPA 303, what is the minimum required separation between fuel fill deck plates and any opening into the vessel's interior?
- 6 inches
- 12 inches
- 18 inches (Correct answer)
- 24 inches
Correct answer: 18 inches
NFPA 303 requires fuel fill openings to be located at least 18 inches from any opening into the vessel interior to prevent ignitable vapors from entering enclosed spaces.
Question 4: A surveyor is asked to value a 1985 fiberglass sloop. Which depreciation method does SAMS recommend for determining fair market value on aging recreational vessels?
- Straight-line depreciation from original purchase price
- Comparable sales (market) approach with condition adjustments (Correct answer)
- Replacement cost new minus observed depreciation
- Income capitalization based on charter revenue
Correct answer: Comparable sales (market) approach with condition adjustments
SAMS recommends the market (comparable sales) approach as primary for recreational vessels, adjusting for condition, equipment, and regional market differences.
Question 5: During a sea trial, a surveyor notes the vessel pulls hard to starboard under power with the helm centered. What is the first mechanical cause to investigate?
- Unequal rudder blade area port vs. starboard
- Propeller pitch asymmetry or blade damage (Correct answer)
- Off-center fuel load causing list
- Misaligned steering cable tension
Correct answer: Propeller pitch asymmetry or blade damage
Blade damage or asymmetric pitch on one propeller blade creates unequal thrust, causing directional pull; this is the most common mechanical explanation for straight-ahead deviation.
Question 6: Which aluminum alloy series is most commonly used for marine hull plating due to its superior saltwater corrosion resistance?
- 2000 series (copper alloy)
- 5000 series (magnesium alloy) (Correct answer)
- 6000 series (magnesium-silicon alloy)
- 7000 series (zinc alloy)
Correct answer: 5000 series (magnesium alloy)
The 5000-series aluminum alloys (e.g., 5083, 5086) are industry standard for marine hull plating because their magnesium content provides excellent seawater corrosion resistance.
Question 7: When documenting a survey finding of structural significance, SAMS standards require the report to include which of the following at minimum?
- A repair estimate from a licensed shipyard
- Location, description, severity rating, and recommended corrective action (Correct answer)
- Photographic evidence with GPS coordinates
- Owner acknowledgment signature before report release
Correct answer: Location, description, severity rating, and recommended corrective action
SAMS report standards mandate that each significant finding include its location, a clear description, an assessment of severity, and the surveyor's recommended corrective action.
SAMS Hull and Machinery Surveyors 3
A surveyor finds that a vessel's propeller shaft has a measured runout of 0.018 inches at mid-span.
What is the most likely consequence if the vessel operates without correction?