4 week cruise? I bet you must have a lot of heavy crap on board,
including water, that can be jettisoned. Do it quick, before the tide
drops any more than it already has. If you have some other heavy stuff
you want to try to save, you can transfer it, along with extra people,
to the dinghy, temporarily.


100% correct. And if you're not too far away from land, turn on your fawcetts
and run out your fresh water tanks. You'll have plenty of drinks that you can
dump into the dinghy. The movement of the keel against the rocks indicates that
the boat is "floating" to some degree. You just need to help!

RB