In general, an un-reinforced vessel can safely navigate in ice provided the concentration does not exceed how many tenths?
Official USCG Answer & Rule Citation
Correct Answer: Option B — 1 - 3 tenths
Standard polar seamanship guidelines dictate that un-reinforced commercial vessels should limit ice navigation to concentrations not exceeding 1 to 3 tenths to prevent structural plating damage, framing distortion, and propulsion machinery compromise.
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