Sandbanks Ferry, which links the Dorset Coast Path to the Bournemouth Coast Path, will be out of action from Monday 23 October to Sunday 19 November.
The vessel is due to make rare journey pulled by two tugs to Southampton for a three week refit which will include cleaning and repainting. This is the quietest period for traffic before the winter when sailing along the coast and painting is often more difficult.
The 150 Wilts & Dorset bus service which uses the ferry route will operate as a shuttle between Sandbanks and Bournemouth. Routes 142/143 which run from Swanage to Poole via Wareham will be extended to Studland and Bournemouth.