A fleet of ships.
A convoy.
A group of sheep is call
A flotilla.
may
The name for a group of ships, beginning with an "s", would be squadron.
you call them a fleet but if they are wardhips you call them armada
A group of sailors is a ships crew.
A Floatilla
Ships crew
In common people say a group of ships is called a fleet but it can also be written as flotilla instead of fleet. However, according to grammar both are collective nouns.
An armada . Another answer: A group of ships together for protection is called a convoy. An armada is specific to armed war ships preparing to attack.
you would call then a group of rodents.