One good reason to carry and use local charts onboard is to avoid running aground, which can cause injury to passengers as well as damage to your boat. A grounded boat describe a vessel that touches the bottom and gets stuck. Not all shallow areas or submerged hazards are marked by a danger buoy.
According to U.S. Coast Guard (USCG) statistics, groundings have accounted for a number of fatalities, injuries, and millions in property damage every year.
When you run aground in an inboard/outboard vessel, you should shift the weight away from the grounded area of the hull, lift the outdrive part-way then shift into reverse.
A kedge anchor can be your working anchor. If you have a dinghy, you can put the anchor in and row or motor off the stern and set it in deeper water. If you don't have a dinghy, you may be able to walk or swim it out. Use two or more PFDs or throwables to float the anchor on while you walk or swim it out. Make sure the anchor line pays out smoothly. Be sure that you wear a PFD and have a line tied to you and the boat in case you get too exhausted to swim back.
If you were moving slowly when you grounded and hull damage looks to be minimal, you may be able to simply back off by shifting the weight farthest from the point of impact and using an oar or boat hook to push off. As you start to move, be sure to check once again to make sure you are not taking on water from a hole caused by the grounding.
If backing off is not a viable option or if it doesn't work, you could consider using a kedge anchor to kedge off. You do this by pulling or winching in on the anchor line attached to the kedge anchor you set as outlined above.
Should your hull be severely damaged, stay put and call or signal for help from another vessel or commercial marine towing company. You are not going to sink if you can step off the boat onto terra firma.
Your final option, short of waiting for the tide to come in, is arranging a tow. You should consider carefully whether to accept a tow from another boater who is inexperienced. Towing can be hazardous and can cause bodily harm and damage to one or both boats unless someone in the party is aware of the precautions that must be taken. If this is the case, call a commercial towing company. Do not call the U.S. Coast Guard unless you are in imminent danger.
PWCs going aground create different problems. In most cases, the operator can simply get off and push or pull the PWC into deep water, get onboard, connect the kill switch lanyard, and get back underway. You should not try using the engine to get off because of the possibility of introducing sand, mud or grass into the jet drive intake.
Be sure to immediately inspect the PWC hull both inside and out for cracks and leaks when you initially go aground. In addition, make sure that nothing has jarred loose and do the "sniff" test to be sure no gasoline leaks have developed.