Cobalt Blue Glass Tumbler with Frosted Sailboat Design

This item is a short, cylindrical glass tumbler made from rich, translucent cobalt blue glass. The overall color is a deep, vibrant blue. The tumbler features a frosted, etched white design depicting a sailboat on wavy water, with several birds (possibly seagulls) in flight above and around the sailboat. The sailboat itself has a prominent, large sail and a streamlined hull, rendered in a simple, artistic style. The frosted treatment gives the design a matte texture that contrasts sharply with the glossy, transparent blue of the glass. The glass appears to be of standard thickness, suggesting durability for regular use. Given the frosted design and the color, it likely dates from the mid-20th century, possibly 1950s-1970s, a period known for marine-themed glassware and colorful kitchenware. There are no immediately visible chips, cracks, or significant wear marks on the glass itself, suggesting good to very good condition, though a closer inspection would be needed to confirm microscopic scratches or fading of the frosted design. No maker's marks or signatures are discernible from the provided image. The craftsmanship appears to be typical for mass-produced decorative glassware of its era, with the etching likely applied through a sandblasting or acid-etching process.