- Every sea-going vessel in the port(a)shall, when in tow asteru, carry the lights required by rule 5 of the International Regulations for preventing collisions at Sea.(b)shall, when in tow of vessels lashed alongside both sides, carry only the white lights required by rule 3 of the said Regulations.(c)shall, when in tow of only one vessel lashed alongside, carry the white lights required by the aforesaid rule and in addition a side light on the side away from the towing vessel.(d)shall, when in two astern of a vessel and with tugs lashed alongside, carry the white lights required by the aforesaid rule.
