The Veluwemeer Aqueduct, also known as the Drontermeeraqueduct, is a unique structure in the Netherlands that carries a canal over a large lake.This impressive water bridge spans the Veluwemeer lake, connecting the provinces of Flevoland and Gelderland
A lot of the sail ships used on inland waters here have flat bottoms, like for instance the skûtsje. So they can sail in quite shallow waters.
[edit] I’ve looked it up and for instance a tjalk (historic freight ship) can have a mast height of around 20-25 meters, but has a sailing depth of only 80-200 cm. Due to their flat bottoms, they can easily move around the inland lakes and canals, which are often only a few meters deep.
Most 10-meter-ish sailboats have less than 3 meters-deep keels, usually less than 2 meters.
Ah, interesting. Thanks.