Commodore
Honourable merchant navy rank
Besides being a step on the ladder in the military naval rank carreer path. Commodore is an honourable rank in some shipping companies in the merchant navy. The longest serving and/or oldest captain with a shipping company can be awarded this title, if the company has a fleet of ships. It holds no value, nor does it result in any increase in rank or privileges, its pure prestige.
Known commodores
Pieter-Jan Egberink joined the Trading for Profit Shipping Company at 14 years old where he first served as a sailor with the deck crew and made it to the rank of Boatswain, at 18 years old he went to a Nautical University, and got his license to sail as an officer. Now at 60 years old he's still sailing for TPSC as a Captain. Making him the longest serving crew member of the company.
Flotillas
Sometimes it is necessary for ships to sail in a convoy or a small fleet, a flotilla. Two ships together is already a fleet in theory. In case of two ships, the captains may decide among themselves and make decisions by talking to each other. But when flotillas get bigger, it may be good for decision making to appoint one overall person who is in charge, that person would be a temporary commodore for the planned journey of the fleet. In war times the commodore of such a fleet of merchant ships might even be a military navy officer to assit the ships with his knowlidgable advice. If the fleet is not escorted by a military navy ship.
Flag
A commodore may be considered a flag-officier. Espesially in a fleet this means that the ship the commodore is sailing on is identifyable with a flag. This flag is traditinonally a broad swallow tailled pennant.
On their uniform a commodore might decorate it with a line down the side of their trousers, and oak leaf decorations on the cap of their hat. Although not all captains choose to use this symbols of rank.
Read more about flags here: Nautical Flag Etiquette
Insignia
Rank insignia captain vs. commodore
Traditionally the captain has four bars on his jacket sleeves and/or shoulders, some nations have a loop in the top one, some have crossing bars in the middle, others anchors or stars. But the four bar basis remains. For a comodore this changes to a solid block, all four bars placed together or with the space inbetweed filled out with gold, and the same symbol on the top.
See here how the Pirate crew of the Sunset Dawn bend the captain's rank insignia to their own desires for their captain:
Nice tooltips again, you really started having fun with them at the end of summer camp, didn't you? XD Does the company only have one commodore? Is it more prestigious for a company to have more of them than a rival company for example?
Yes my mood did change over the course of summercamp :P Less carring about making everything 'wright' or less afraid to put more humour in it. Mixed with a bit of pressure to make it before the 31st.
No only one commodore per company.
I didn't think about rivaling commodores yet. hmm nice thing for in a story :D