In addition to xpda's answerxpda's answer:
Any time you're out sailing and hat or something falls in the water, it's time to practice a MOB drill. Run the full protocol, including yelling out "MAN OVERBOARD" (even it's it's a female hat).
Set up deliberate drills by throwing a fender overboard.
Practice in a variety of conditions (especially wind strength) and various points of sail.
If you use a motor and you're unskilled, you could hit the MOB with the boat or prop. Don't do that!
You can rescue a MOB under sail, and it's a good way to improve your sailing skills. There are many approaches, and sailors like to argue which is best. Maybe you tack, maybe you jibe. Approach from below the MOB, so you can point in to the wind and come to a stop just at the MOB (much like docking under sail). This gives you time to try multiple attempts to get the MOB out if necessary, whereas a downwind approach lets you have one try at it. To get to the downwind side, usually use a figure 8 pattern - this makes it easier to keep eyes on the MOB.
To pull someone out of the water when they're wearing a PFD:
- Grab by the shoulders of the PFD
- Push down
- They will pop up; use the momentum to help pull them in to the boat.
Know which part of your boat will be easiest to pull someone in by. On a small tender boat, that may be over the transom.
If your topsides are high, you may need to use a rope. Tie a large bowline to go around the MOB's chest.