The Steam Packet Company says two TT sailings to Liverpool will be from Heysham instead.
Pier Head operator Global Ports Holding says the sailings on June 2 and 3 won't be able to use the Mersey landing stage.
The Manannan will operate the crossings, which will take two and a half hours hours, rather than the usual three hours from Liverpool.
The company says coaches will take foot passengers from Liverpool to Heysham and vice versa.
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