The government says the proposals from Quest Navigation Inc. and Maritime Applied Physics Corporation will be evaluated by a committee with government and private sector representatives.
The evaluation should be done in about a month.
The province has said it will provide up to $21 million over seven years, but it wants to make sure there is a sound business case for such a service.
As well, the government says money from the federal government is required.
The province's NDP government has endured widespread criticism in southwestern Nova Scotia for its 2009 decision to eliminate subsidies for the money-losing ferry service.