The centre's last day of operation is today.
The Mayday Coalition has planned a rally at the small boat basin in St. John's Harbour.
The federal government announced the closure last June, saying it would not affect safety.
Distress calls that used to be handled in St. John's are now being routed to Halifax.
The Canadian Coast Guard says the rescue sub-centre in St. John's handled an average of 500 incidents annually.