Quartermaster

The right hand

It's been a while since the last time they had the chance to put a foot on solid ground, Etha.

— Yarik to Etha

Save for the Captain, and often considered equal to them by most means, the highest rank achievable in a ship is that of Quartermaster.
This role is usually reserved to experienced and technically competent sailmen who are capable of stepping in to aid and supervise in a variety of tasks onboard a ship, and act legitimately as the right hand of the ship Captain.

I don't think I'd be any good as your Captain, I'm better where I am, if you still want me.

— Yarik

As for the role of Captain, that of Quartermaster is granted by election of the crew and its holder is, as a consequence, a sailor trusted by both the Captain and the crew for their integrity and negotiation skills.
They are often a mediator between the Captain and the sailors and often the person in charge to dispense prizes and punishments to the crew. In ferret paw's pirate ships, they are also the ones deciding the fate of the resisting captured crew, while in the ones who fly the ferret's jaw, they often have the task of finishing any subdued resistance,
It is, for this reason, often said that the Captain is the one who holds the ship and the Quartermaster is the one who holds the crew.
As far as tasks go, the responsibilities of a Quartermaster are varied and depend on the individual skills, but they often double up as the rigger, bosun or navigator depending on the needs and are often in charge of governing any captured ship that the Captain wants to keep until a new election is organized among the crew.

by Austin Neil

Dispenser of praises and punishments

One of the expectations of the Quartermaster is to keep the discipline on board on behalf of the Captain. Their closer relationship with the crew makes them the best suited at finding the appropriate degree and type of punishments to inflict to each of the sailors and the best ways to reward them for good behaviour and performances.
A good Quartermaster keeps the crew happy and united through fair, if not necessarily equal, treatment for all.
These, and their responsibility to distribute the rations (and the booty, in pierate ships) can make them a beloved leader of their people or a despised tyrant who will be thrown overboard at the first chance.