Seamark® is the best of both worlds when it comes to boat top fabrics. Sunbrella® acrylic marine fabric is coated on the underside with marine vinyl. The color of the vinyl correlates with the Sunbrella® top. Because of the vinyl coating, the top is now waterproof. For best results, the Navy or Bimini top should be made from Seamark® and the rest of the enclosure or boat cover should be made from regular Sunbrella® to enable air to circulate.