This might be a good time to wean off of the "time wasters." Have them bring a few of their engaging low-tech toys. This is also a great time for reading, the adults can also set an example.
Being lookouts, taking bearings, watching for navigation aids, spotting other boats, looking for wildlife, dragging a fishing line, helping to coil lines and keeping the boat neat.
I like the kite idea, must try that myself. I do sail with families occasionally.
The vee berth play space is good; kids need their own space.
Jack