Personalized Grandpas First Mate Nautical Sailboat T-Shirt. Grandpa's 1st Mate T-Shirt - White has little sailboat in red white and blue for a boy who loves sailing with their Dad. Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.