It was only after my son turned his back to the water and jumped off the 5-meter platform, his arms reaching into space, his legs flying up and over in an inversion that rang alarm bells deep in my Dad brain, that I realized he was attempting a backflip from high above the Müggelsee, Berlin's largest lake.
This was a new trick — we're not really a backflipping kind of family — and there was just enough time for me to think about travel insurance and why 13-year-old boys seem drawn to risk like moths to a blowtorch before he splashed into the lake, mostly upright.
Emergency averted, I took the long view: As long as no one ends up in a body cast, throwing ourselves into summer is why we're here, right?
My wife and I took our two sons to Berlin in early August hoping to catch some of the city's summertime vibe.
During the fall of 2016, we'd spent part of a sabbatical in the city. The beaches were closed for the season by the time we showed up, the paddleboards slid up into the rafters and pleasure boats marooned in winter storage. The feeling that we had missed something became more evident as weeks passed.
That autumn was blustery, and yet whenever we researched our Berlin neighborhood online, images popped up of sandy beaches, lakeside resorts and people lounging in swimsuits or skipping across the Müggelsee on a windsurfer. "Next time," we began saying.
That turned out to be this August, and by then we had a shortlist of beaches, lakes and rivers to see.
Like Duluth, you can't see the ocean from the German capital, but you can drive there in a boat. The city is landlocked, but coursing through its center and spiraling away from it are waterways that carry freight, passengers, tourists like us and all manner of watercraft. Berlin contains more bridges than Venice, about 120 miles of canals and rivers and a vibrant boating scene. The canals that crisscross the German capital eventually link up to the country's major rivers: the Rhine, Elbe, Danube and Main. Thousands more miles of canals and rivers connect from neighboring countries, making it possible to spend weeks exploring Europe by water or venture to the North Sea.