2 Electro-Motive Unit. (abbr.) (3)
3 Traffic that is entering or returning to port. (7)
5 Not difficult. (4)
6 Vessel Traffic Information System. (abbr.) (4)
12 Fencing at the parameter defining the limit. (8)
13 Electrician assistant. (8)
17 Give out fumes or signal. (4)
18 Parts of an hour, in short. (4)
19 Handicap. (7)
20 Universal time (coordinated, abbr.) (3)

1 Brought cargo from abroad. (8)
3 International standard serial number. (4)
4 Day of the month. (4)
5 Hard rubber, black in colour. (Don't call Carl for Celebration, cryptic) (7)
7 Detectors or transducers. (7)
8 Large anaconda. (3)
9 Glass Reinforced Plastic. (abbr.) (3)
10 Repair or mend. (3)
11 Safety At Sea. (abbr.) (3)
14 Fills water to stabilize a ship. (8)
15 Type of; category of things. (4)
16 Flame burning everything. (4)