Had some problems with the nav system at the dock but chalked it up to insufficient battery power and assumed that once the engines were going that the charge from the alternator would alleviate the GPS problem. That idea was a bust and we had problems all the way back to Brant Beach. We ended up using the iNavX program on the iPhone which worked admirably. When you're as green a navigator as I am never leave the dock without plenty of backup electronics.
I've run aground before in the channel that goes toward LBI from Little Egg Inlet. There are two marked channels there and you can't pass from one to the other without going over a sand bar that's much too shallow for Voracious C so I know to be careful. But we ended up stuck and waiting for high tide before Tow Boat could come and haul us off. Didn't get away unscathed this time. Based on the vibrations I'm thinking we bent a prop.