Just because a commercial vessel plies the crystal-clear cerulean waters of the Bahamas doesn’t mean it has a carefree life. For Gerry Fleming of Aqua Cat Cruises, it meant constant attention to the sand and silt that wreaked havoc on the bearings of his fleet of liveaboard dive vessels that operate in the area. That is, until he switched to Vesconite, the high-performance, low-friction polymer that was engineered to shrug-off particulates.
Aqua Cat, the company’s 105 x 36-ft flagship, was delivered with rubber-lined phenolic rudder and stern tube bearings. Drawing under 6-ft, the vessel’s skeg would often touch bottom, kicking up sand and silt. The result was no water flow and burned-out bearings. “After a hurricane, silt is drawn up from deep water,” said Fleming. “It plugs up everything.”
Working around his vessels’ year-round, 24/7 booking schedule, Fleming implemented standardized maintenance for his fleet, hauling every two years. Aqua Cat has three bearings on each main shaft, four rudder bearings and two sand shoe bearings. “It’s expensive to change-out bearings,” Fleming continued. “With Vesconite, bearing service is now beyond six years.”
Self-lubricating Vesconite is the ideal marine bearing material. It has no stick-slip, doesn’t swell in water and provides a wear life ten times that of bronze. The polymer machines to +/-0.001-in., making it suitable for applications with tight tolerances. Originally conceived for use in muddy underground mines, it excels in dirty conditions that leave other bearing materials prematurely wearing shafts.