So we dithered and bothered, and I went off and worried in the shower, but the bottom line is that even with today's NNE4 we would have been heading into wind and sea for 25 miles, which is no fun, and in any case we couldn't have reached Rügen in daylight, which we think is essential for negotiating the long, shallow, narrow entrance channel. If we left this evening or tomorrow the wind might free off a bit, but we'd still be very close-hauled on a lee shore, with a strengthening wind, building waves, and a north-facing long, shallow etc entrance channel. And on Friday the wind goes up to 6-7 for a few days and all bets are off.
So we are going to run away from sea tomorrow - leave the boat here, get the train to Berlin and then east to Hangelsberg, and spend a few days at the Herrmann holiday home in Wulkow, where we will indulge in hot baths, full-sized beds with no bicycles or kayaks in them, no rocking about or water slapping on the stern, and long walks in the forest 200km from the sea.
Oh yes, and in the meantime we spent today in Rostock, which is more pleasant than we expected (it hasn't really recovered from losing its position as the premium shipbuilding location for the Warsaw pact countries after reunification), but not hugely exciting.