SCIENCE AND THE SEA 



CASE 3 



The principals in this case were a dry-cargo 

 vessel and a bulk carrier which collided during a 

 period of restricted visibility in the Atlantic Ocean 

 approximately one mile south of Chesapeake Bay 

 Entrance Lighted Whistle Buoy JCB. The 

 casualty occurred in international waters, and both 

 ships were credited with having been displaying 

 proper navigation lights and sounding appropriate 

 fog signals. The weather at the time was foggy 

 with visibility from 500 yards to one mile. The 

 wind was from the ESE, force 5. 



Both vessels were equipped with radar, and 

 both reported that it was in use and functioning 

 properly at the time of the collision. 



NARRATIVE 



SHIP A 



Ship A departed Baltimore, Maryland, with 

 general cargo enroute to Jacksonville, Florida. 

 After completing an uneventful transit down the 

 Chesapeake Bay, the pilot disembarked at the 

 Maryland Pilot Boat anchored about 1.8 miles 

 east-northeastward of Cape Henry Light. The 

 weather consisted of patchy fog with visibility 

 ranging betv/een 500 and 4,000 yards. Following 

 the pilot's departure at 2051, the master set a 

 course of 128°T to pass south of Chesapeake Bay 

 Entrance Buoy 2CB, some 9 miles distant. A 

 lookout was stationed on the bow, and the pre- 

 scribed fog signals were being sounded. The 



engines were placed on standby. On the bridge 

 with the master, who was conning, were the watch 

 officer and a helmsman. The master frequently 

 observed the radar screen which was set on the 

 relative motion display. During the passage from 

 the pilot boat to Buoy 2CB, several course and 

 speed changes were made due to conditions of 

 visibility and the avoidance of inbound traffic. 



According to the master's account, Ship B was 

 observed at 2124 as a radar contact bearing 001° 

 relative at a distance of 4 miles. The master 

 incorrectly estimated the contact to be about 1 

 mile east of Buoy 2CB. Shortly after this initial 

 contact. Ship B was observed to have moved from 

 Ship A'>< starboard bow to close on her port bow. 

 From this apparent relative movement it was 

 assumed that Ship B was inbound and would pass 

 safely to port with a CPA of about 1 mile. No 

 attempt was made to plot the radar contact to 

 determine its true course and speed. 



At 2127, Ship A increased speed to approxi- 

 mately 12 knots (maneuvering speed). Shortly 

 thereafter, the master, watch officer, and bow 

 lookout all heard fog signals off the port bow. 

 The master assumed that the signals were being 

 made by the radar contact he'd been observing, 

 thus confirming his previous deduction that a safe 

 port-to-port passing would take place. At 2130, a 

 glare of lights was seen broad on the port bow in 

 which the master and watch officer saw what 

 appeared to be the range lights of Ship B. From 

 the position of the lights, they determined that 



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