COLLISION AVOIDANCE MANEUVER (Method I)

1. Enav222 midterm lessons

2. METHOD I (PROCEDURES) ALTER COURSE AND MAINTAIN SPEED

3. SITUATION: Our ship is on Course 0000 T speed 11 knots. Our radar is set on 12 mile scale. A contact is observed as follows: TIME BEARING RANGE 0603 0600 11 miles 0609 0590 9.5 miles 0615 0580 8.0 miles CHANGE OF COURSE

4. Find: RCPA TC TCPA TS MCPA Target Aspect MRM DRM SRM PART 1- PLOTTING THE 1ST VECTOR (e-r-m)

5. Oc=0000 OS=11knots X M1/0603 M2/0609 M3/0615 RML R Spd=11kts. Tdiff.= 12 min Dist= 2.2miles

6. 2.2

7. Find: RCPA TC TCPA TS MCPA Target Aspect MRM DRM SRM END of PART 1- PLOTTING THE 1ST VECTOR (e-r-m)

8. PART 2-Plotting the 2nd Vector (e-r1-m)

9. MX BMX TMX RMX NDRM NSRM NTCPA NBCPA NRCPA Find and Plot the ff:

10. r m 6miles NRML 3miles e MX NDRM 2.2 WHAT WILL BE OWN SHIP’S NEW COURSE?

11. r NRM & RL m NRML r1 e MX NDRM 2.2

12. NCo r NRM & RL m NRML r1 e MX NDRM

13. Nco=054o r NRM & RL m NRML r1 e MX NDRM RML R DRM

14. MX BMX TMX RMX NDRM NSRM NTCPA NBCPA NRCPA Find and Plot the ff:

15. Of change course problems END

16. METHOD II (PROCEDURES) MAINTAIN COURSE AND ALTER SPEED

17. Own ship’s course could be changed to either 054o or 294o . However, there is a reef to starboard and three ships to port that prevent either course changes. Required: What other course of action could be taken? Answer: Reduce speed = 5.2knots CHANGE SPEED PROBLEMS

18. r NRM & RL m r1 NRML e MX Spd.reduce to 5.2kts. NDRM RML R DRM

19. METHOD III (PROCEDURES) ALTER COURSE AND ALTER SPEED

20. Instead of continuing own ship at the speed of 11 knots and instead of changing course to either 054o or 294o we decide to increase speed to 15 knots. Required: What course change will have to be made so that at 15 knots, the CPA will continue to be 3 miles? Answer: 065oT CHANGE OF SPEED AND COURSE PROBLEM

21. r MX m e Tdiff.= 12 min Dist= 3.0miles Spd=15kts.

22. NRM & RL r1 e 3miles

23. NCO=065O r m NRM & RL MX r1 NRML e NDRM

24. HOW TO PLOT NEW COURSE

25. NCO=065O r m NRM & RL MX r1 NRML e NDRM

26. END