The charted channel depth at Eastport, ME, is 28 feet. You are drawing 31.5 feet and wish 2 feet clearance under the keel. What is the earliest time after 1700 (ZD +4) on 6 September 1983 that you can enter the channel?

Correct Answer: Option C — 1915

Total water depth needed equals vessel draft (31.5 ft) plus required under-keel clearance (2 ft), totaling 33.5 feet. Subtracting charted depth (28 ft) requires 5.5 feet of tide. Consulting Eastport tide tables, this height is reached at 1915.