In 1906, the Port of Cape Vincent's breakwater was completed, creating a safe harbor for large ships. Today, the Cape Vincent Seaway Pilots' office and dock in the Port of Cape Vincent supplies lake and river pilots for vessels traveling Lake Ontario and the St. Lawrence River. From March until December, the pilots operate 24 hours a day.
The Port of Cape Vincent is home to Martins Marina, a full-service marina with two boat launches and a service department. This Port of Cape Vincent marina also has a gas dock, a large parts department, a motel, boat rentals, and a shoreline campground. Martins Marina in the Port of Cape Vincent has 100 floating slips, a marine supply shop, a bait and tackle shop, and a grocery store.
The rate for a day's dockage at the Port of Cape Vincent's Martins Marina is $12, and the fee for the launch ramp is $5 per day. Seasonal dockage is available for from $18 to $28 per foot. Boat rentals are also available from $25 to $80 per day for 4.9-meter (16-foot boats). Pontoon boats with capacity for eight people are available for $140 for one-half day or $200 for a full day.
The Riverside Cottages/Marina is available for dockage and for winter storage in the Port of Cape Vincent. Located in a protected basin on the St. Lawrence River, the facility can accommodate vessels to 8.5 meters (28 feet), and both water and electricity are available at the docks.
Precision Marine in the Port of Cape Vincent is a full-service marina in Peos Bay. It offers a launch ramp, dockage, and bathrooms with showers for customers. On-site inside and outside storage is also available at this Port of Cape Vincent marina and repair service. Precision Marine has a shop that offers marine engine service, welding, hull repair, propeller reconditioning, and fiberglass work. Precision Marine also offers a towing service.