Slipstream

A northern marina is two facilities sharing one name: berths in the water from April, a storage yard on land from October. Every incumbent models the first well and treats the second as an attribute on a record. Slipstream gives the winter its own model — because storage is not an assignment problem but a packing problem with an extraction order. A hull in the middle of a row has four boats parked in front of it, so launch order is a physical constraint, not a scheduling preference.