Refitting for speed is one of the most common rebuilding projects. That can involve simply streamlining the underwater running gear and re-powering the yacht with a more efficient, higher-performance propulsion package. It can also include extending the hull and replacing solid-wood bulkheads, decks, overheads and other structural panels with cored composite materials to minimise weight. For sailboats, it might also mean replacing masts of aluminium or wood with carbon fibre.

Extending the hull has become a common refit operation, especially for older motor yachts with squared-off rear sections or transoms. An extension can create flowing lines to update the appearance of the yacht for higher resale value, while providing more deck and storage space.

The least expensive type of extension is the addition of a swim platform or an open cockpit to the original transom. A more complex project might include curving staircases and an overhang over the extended section.