What the charter companies are looking for, is your desire to charter one of their vessels, your ability to pay for the service and they are looking to feel comfortable about your ability to safely operate the vessel. This last point is the key to success, both for you as the charterer and for them as a business. Once said all this makes perfect sense. The charter companies have devised a number of methods to ascertain your ability to skipper a vessel. The good ones actually send you an extensive questionnaire upon initial contact and filing this out gives them a resume of your experience.
Formal training is also a plus.
After reviewing your credentials they may inform you that you have met their minimum qualifications and that they will charter you a vessel. Actually the charter companies will usually phrase this in such a way that give themselves an out. At the same time this representative of the charter company is checking you and your group out. If they have any doubts as to your ability, the charter company will ask you to demonstrate your competency. You will be asked to move the vessel out of the slip, hoist the sails, tack a bit, maybe even do a man-overboard drill.