Sin Tung Hing Marine, also known as STH Marine, is a marine equipment and boating retailer based in Papeete, French Polynesia. Its catalogue serves boat owners, water-sports enthusiasts, divers, anglers and people who enjoy life on the water. Customers can explore boats and trailers, including aluminium, fibreglass, inflatable and rigid inflatable models, as well as boat packages from brands such as Highfield, Stessl, Polyform, Jeanneau, Quicksilver and AB Inflatables.

The company also offers Mercury combustion engines and Torqeedo electric motors, alongside servicing supplies, oils, maintenance kits and spare parts. Its marine equipment range includes anchoring and deck hardware, safety gear, navigation electronics, VHF radios, marine electrical products, seating, covers and cleaning and protection products. For leisure activities, STH Marine stocks diving and snorkelling equipment, fishing tackle, spearfishing gear, kayaks, towable products and water-sports apparel. It also carries marine resins, fibreglass materials and paints. Customers can contact its sales team for advice on boats and engines.