A good sailbag is labeled. Like what sail it has in it. Light main, #1, 140%, blade, etc.
A good gear bag will include heavy construction, some type of water resistance if not water proof, outside pockets, inside pockets, shoulder strap, and an easily recognizable shape or color.
What's in it? Sea sickness drugs, gloves, glasses, PFD, teather, knife-multitool, sunscreen, a SNACK, foulies, boat shoes, spare socks, climbing harness, etc. All of it must fit in one bag. Owners don't like it when you show up to crew for the day, and it looks like you're staying for a week.
Merit 25 # 764 "Audrey"