The issue, affecting the 11:00 sailing from Lymington, first came to light at 11:30, as first reported by Island Echo.
A planned emergency berthing procedure is being put in place at Lymington, with a one boat service expected to resume as soon as this is in place.
Additional sailings have been added to the Fishbourne to Portsmouth route, with customers advised to travel across the Island to the Fishbourne port to travel to the mainland.
The additional sailings are:
From Portsmouth: 1430, 1630
From Fishbourne: 1530, 1730
UPDATE @ 14:45 – Wightlink have resumed a one-boat service between Yarmouth and Lymington, however lengthy delays are expected.
Engineers are on site in Lymington and are working to return Wight Sky to service as soon as possible.
UPDATE @ 18:25 – Wightlink say they are running a two-boat service and are working hard to clear delays.
Photograph thanks to Colin McCrae