As you get bigger boats you will have more crew to manage onboard your boat, which can do certain tasks.
To tell a crew how to perform a task, you move the crew icon from Resting area over to the task you want him to do, example from Resting -> Prepare Gear.
Type of tasks your crew member can do will vary, depending on the type of fishing rig your boat is set up with.
Cook - Cook food for your crew to boost stamina. Move the food icon over to the crew icon, to consume food.
Repair - Repair your boat and damage gear onboard
Prepare Gear - Here you select the gear you want to prepare to be set. Click on the available gear, and then click again on type of gear (ex. 1000 hooks) to set crew members to prepare gear.
Longline Haul - These options will vary depending on rig set up.
Amount - Show how much catch that is stored in this section, bigger boats with freezing capabilities, require the fish to be processed before you can sell it in ports.