For the river cruise industry, which operates on fixed itineraries booked years in advance, the fallout has been palpable. (Most river cruise ships require at least four to five times that water depth to operate safely.) Captain Niels Springer, who commands the AmaSofia, was candid about the river conditions when speaking from the bridge. CHRISTIAN BRUNA // Getty Images Two river cruise ships docked near Marbach an der Donau, Austria on the Danube. “River conditions naturally fluctuate from year to year, and no two seasons are exactly alike,” the AmaWaterways COO says.