A large drop in sea passenger figures in May is being blamed on the TT being a week later than usual.
Just under 15,000 fewer people and around 9,000 fewer vehicles travelled on the Steam Packet compared to May 2008.
Both practice week and race week were in June this year.
Captain of Harbours Mike Brew says excluding the impact of TT traffic the figures remain positive, adding the coming months should see the benefit of the Manannan's increased capacity and passenger comfort.
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