Sailing is the worst aspect of the game imo. Help me out.

[Red Nations]

Awareness of your surroundings is extremely important in ship combat. Don't place your ship in a position where a group of enemy ships can rat pack you. Also its a good idea to avoid areas where you see individual or groups of low level pirate ships such as light sloops and light galleons. These usually indicate low level usually basic players, often kids who tend to shoot at anything and everything around them. If you're out plundering and a bunch of these low level pirates come up on you odds are they will get your ship sunk or heavily damaged because their random fire will draw all enemy ships in the area in toward you. For me it was easy to level up sailing, I had it mastered by level 23 with my first pirate. Early on in the game I bought the best ships I could starting with a regular galleon as soon as I could buy one. Having good ships helped in finding crews willing to sail with me for plunder and out of those early crews I did find some good pirates. I quickly got rid of any crew that were random shooters or who tried to grab the wheel without permission.

One thing I would suggest is to split your time between sailing and crewing on other ships to level your cannons. You can find good people to crew with by going around and talking to some higher level pirates. Asking them if they are going out to plunder and if so asking them if they could use an extra gunner? Often times this approach will get you crewed up with a good captain. I always avoided accepting those random crew invites by strangers who click on you and send you crew invites. Its always best to talk to people first spend a few minutes getting to know them before crewing with them, and you can make some good pirate friends this way.
Same with the random friend invites. I make the mistake my first few days of playing of accepting any random friend invite I got, as a result I ended up with a whole crew of idiots teleporting on board my ships every time I launched and getting me sunk. Ended up completely cleaning out the friend list and becoming very careful in regards to who I allowed on my friend list after that experience.