What happens when a boatload of Dortmund fans come across a boatload of Bayern supporters

Scenes.

The top two sides in German football for the past seven years will battle it out for the DFB-Pokal today.

Bayern Munich are bidding to complete a league and cup double and their arch-rivals Borussia Dortmund are keen on lifting a trophy to crown Thomas Tuchel's first season in charge.