Although rule 26 is quite clear in its language it allows for several possible combinations of.

Sailing vessel sound signals. A sailing vessel less than 7m long should show side and stern lights if possible or carry a torch to illuminate the sails when necessary. These signals are not to be used when visibility is limited by fog. A vessel that is underway but stopped is not making way.

Only emergency fog signals should be used in scenarios with low visibility. C A vessel not under command a vessel restricted in her ability to manoeuvre a vessel constrained by her draught a sailing vessel a vessel engaged in fishing and a vessel engaged in towing or pushing another vessel shall instead of the signals prescribed in paragraphs a or b of this Rule sound at intervals of not more than 2 minutes three blasts in succession namely one prolonged followed by two. Sound signals are typically used in conditions with good visibility and are not appropriate in high fog.

Index Go to Part E Rule 38. Sound signals for vessels in fog A vessel is underway if it is not at anchor on a mooring or tied up in some other way. And besides we kinda like to toot our horn.

Fishing vessels are also prime suspects for navigation light confusion. Here are some of the most important sound signals you can use to communicate with other vessels. A vessel of less than 12 metres in length shall not be obliged to carry the sound signalling appliances prescribed in paragraph a of this Rule but if she does not she shall be provided with some other means of making an efficient sound signal.

A vessel aground may in addition sound an appropriate whistle The word whistle means any sound signalling appliance capable of producing the prescribed blasts and which complies with the specifications in Annex III to these Regulations. A motor vessel less than 7m long may carry a single all round white light. There seems to be know rhyme nor reason.

Some vessels show them all the time others sometimes and some never at all. One prolonged blast is a warning signal for example used when coming around a blind bend or leaving the dock. LARGER VESSELS Under 50m in lengthFor vessels under 50m in length a second masthead light is optionalFor vessels under 12m in length sidelights may be a combined lantern -on fore and aft centreline.