Paddling a long distance along a shoreline that doesn't change much, or across a big body of open water can get boring. Boredom often translates into feeling uncomfortable, making you take more stops for food or water. If you're in a group there's a tendency for each person to take a break at a different time and this can severely slow the progress of the group. So decide how often you all need to take a break and then stop together for regular timed breaks. For example this might be a five minute break every hour, starting on the hour. That way everyone can anticipate the break, and it's easier to push on knowing exactly how long you've got left till your next break.