The 22.5° and 45° rule is doubling angle on the bow which is the distance run is equal to the object's distance at the second bearing. In this, case 7 tenths of the distance run equals the distance the object will be passed abeam.
The questions below are some Coast Guard exam questions which you may find on the terrestrial exam.
(22.5° and 45° Rule)
1. Your vessel is on a course of 297° T at 11 knots. At 0019 a light bears 274.5° T, and at 0048 the light bears 252° T. At what time and at what distance off will your vessel be when abeam of the light?
A. 0102, 2.6 miles
B. 0108, 3.7 miles
C. 0057, 4.6 miles
D. 0117, 5.0 miles
2. Your vessel is on a course of 129° T at 13 knots. At 1937 a light bears 151.5° T. At 2003 the light bears 174° T. At which time and distance off will your vessel be when abeam of this light?
A. 2016, 2.8 miles
B. 2016, 3.9 miles
C. 2021, 3.9 miles
D. 2021, 2.8 miles
3. Your vessel is on a course of 343° T at 14 knots. At 2156 a light bears 320.5° T, and at 2217 the light bears 298° T. At what time and at what distance off will your vessel be when abeam of the light?
A. 2232, 3.4 miles
B. 2235, 4.3 miles
C. 2228, 4.9 miles
D. 2241, 6.9 miles
The 26.5° and 45° rule, if the first bearing is 26.5° on the bow and the second bearing is 45°, the object's distance when abeam equals the run between bearings.
(26.5° and 45° Rule)
4. Your vessel is on a course of 311° T at 21 knots. At 1957 a light bears 337.5° T, and at 2018 the light bears 356° T. At what time and at what distance off will your vessel be when abeam of the light?
A. 2027, 5.2 miles
B. 2033, 6.8 miles
C. 2039, 7.4 miles
D. 2043, 10.3 miles
5. Your vessel is on a course of 144° T at 20 knots. At 0022 a light bears 117.5° T, and at 0035 the light bears 099° T. At what time and at what distance off will your vessel be when abeam of the light?
A. 0044, 3.2 miles
B. 0048, 4.3 miles
C. 0052, 5.1 miles
D. 0056, 6.0 miles
6. Your vessel is on a course of 358° T at 19 knots. At 0316 a light bears 024.5° T, and at 0334 the light bears 043° T. At whattime and at what distance off will your vessel be when abeam of the light?
A. 0352, 5.7 miles
B. 0355, 6.2 miles
C. 0359, 7.1 miles
D. 0403, 8.0 miles
