Height of tide and depth of water
When the boat floats off
Bob Exam 1 · on paper you need the tidal curve
Our assumption: the Endal Bay curve is not in the exercise, so the factor 0.59 is turned into a time with a regular curve (rule of twelfths): about 2.9 hours before high water, that is 0949. With another port's curve the time can change by 15-20 minutes.
On 8 October at 0800 the boat (draught 1.3 m) is aground on mud at Endal Bay, at a spot that dries between 1.4 m and 1.3 m. At low water at 0611 the height was 0.4 m and at high water at 1244 it will be 4.3 m. At what time does she float off?
- Draught
- 1.3 m
- Drying heights
- 1.4 m and 1.3 m
- Low water
- 0611, 0.4 m
- High water
- 1244, 4.3 m
- Port curve (booklet): factor 0.59
- at HW−2 h 55
Solution worked out by us from the course material: to be checked by the instructor.