A delegation from Stornoway Port Authority met Transport Minister Keith Brown in Edinburgh to raise concerns at the proposal to upgrade only one of Stornoway's two vehicle ramps to take the huge new ferry, and one at Ullapool.
The port authority stressed it would mean that if anything happened to either ramp, there is no other port in the islands or the west coast outside the Clyde to take that size of vessel.
There is also concern the new vessel, which will carry up to 43 cars on 820m of vehicles lanes, will land the cars in Stornoway, just 300m from the road.
Chief executive of Stornoway Port Authority Jane Maciver said: "We had a useful and positive meeting with the minister. It was agreed the infrastructure requirements will be looked at further."
A spokesman for Transport Scotland said no decisions have been made and the plans were still being considered.