Rowing in a longboat from Harlingen to Terschelling.
The ferry needs two hours for the crossing these brave women needed a bit more time, against a rather strong easterly wind.
And: because the Waddensea has a lot of shallows some longboats were stuck and had to be pulled over the sandplates because some passages were too shallow at the time of passing.
These were lucky to pass just before the strong wind was blowing the last bit of water away.
Here in LARGE....
See also the boats that were stuck