A former fishing vessel started taking on water around 17 miles north-east of Skegness, calling out the RNLI in the early hours on Sunday.
When the lifeboat reached the stricken vessel, the waves were too large to allow them to transfer crew between the lifeboat and the sinking boat.
The crew were forced to tow the vessel back to safety in what turned out to be a nine-hour operation.
The vessel, Sarah, was towed to Fosdyke Marina, where she was hoisted out of the water.
See the video on the BBCs website