True story - years ago I was sailing into Saint Jean de Luz in southern France. Gorgeous summer day with a perfect amount of wind. I was coming into the bay wing-on-wing but decided to drop sails as the bay was filled with runabouts and small craft that were not giving a boat under sail right of way. I was going to go into the port which is way in the back of the bay, but there were so many small craft running around I decided to hang a right and see if I could get into the old port in Ceboure. I knew I was running tight as the tide was going out, and I could only get into that port at high tide. Got up close to the entrance and bounced on the bottom. Knew I wasn't going to make it as there was a shallower bump right in front of the entrance so I tried to turn back out into the bay. Then I hit bottom good and hard with a solid thump and all forward motion stopped. Totally stuck. I was mighty pissed and really didn't want to sit there waiting for the tide to go out, then back in all the while sitting on my boat running a Spanish flag and looking like an idiot...
So I yanked on my 150% light wind genoa, pulled the main sail back up. I was at the perfect angle with the wind and she just healed over coming off the bottom. I kept her healed and sailed under full sail back out to deep water... For some reason, the small runabouts all seemed to suddenly realize I was not giving way to anyone - they all parted in front of me...
No damage to the boat at all, and that was not a sand grounding - that was rock. The keel on my boat, however, was solid, cast ductile iron - very strong stuff. Back then, it was easy for me to check the bottom of my boat, they have 9 meter tides in that region of the world. I'd simply tie up to a warf almost touching bottom at high tide, and then let the tide go out. Inspect the bottom, let the tide come back in - just got to make sure you're on the right tidal schedule...
dj