USCG Exam PracticeApplying tide corrections to charted depth
A vessel drawing 8 feet approaches a shoal with a charted sounding of 6 feet. The predicted height of tide at the time of transit is +4 feet. What is the vessel's underkeel clearance?
- ✓ 2 feetCorrect
- B. 4 feet
- C. 6 feet
- D. 10 feet
Why A is correct
Per Bowditch Ch. 9 §904, actual depth = charted sounding + height of tide = 6 + 4 = 10 feet. Underkeel clearance = actual depth minus vessel's draft = 10 - 8 = 2 feet.
Cited:Bowditch Ch. 9 §904