Gordon Martin, the union's regional organiser, said he would have preferred to have met sooner.
RMT members at CalMac held three days of industrial action last week.
On Friday, The Transport Salaried Staffs' Association (TSSA) will send out strike ballot papers to about 100 of its members who work for CalMac.
The closing date for the ballot is in 10 days time.
Talks between CalMac and the two unions were to be held earlier this week but the ferry operator asked that they be postponed due to unforeseen circumstances.
Two thirds of state-owned CalMac's ferry services were cancelled last Friday during a 24-hour strike by RMT members, who make up about half of the company's workforce.
The dispute has been triggered by unions' concerns about the new contract to run the Clyde and Hebrides ferry services.
CalMac's current deal to operate the network comes to an end next year.
The Scottish government has put the contract out to tender, in line with European rules.
The unions concerns are that, regardless of who wins, the new contract will see changes in employees' current terms and conditions.
A reduction in staff numbers and pensions are key areas of concern.
The unions have asked that the government guarantee in the new contract that compulsory redundancies do not happen and existing terms and conditions are continued.
Caledonian MacBrayne (CalMac) has offered to hold talks early next week in a dispute over workers' jobs and pensions, according to the RMT.