De Greft is the marina of Watersportvereniging De Greft, a nautical club founded in 1967 and situated on the Grecht at the edge of Woerden, the historic fortified town at the heart of the Green Heart region.

The marina itself was built in 1971 in a natural widening of the Grecht, a wetering connecting the Oude Rijn with the Nieuwkoopse plassengebied. A branch toward the Kromme Mijdrecht extends the sailing area further, reaching Amsterdam via Uithoorn.

With around 275 members and approximately 100 berths, the club welcomes visiting boaters and also manages the public guest harbour in Woerden's town centre. The marina is wheelchair accessible, and a harbourmaster is on duty daily.

The surrounding area was historically nicknamed the "Green Bedstee," a local name rooted in the landscape's sheltered, intimate character.