The Sumner line of position navigation method, named after American naval officer Thomas H. Sumner, is a technique used in celestial navigation to determine a vessel's position at a specific time. It relies on observations of celestial bodies, typically the sun or stars.

The Sumner method is particularly useful when celestial bodies are close to the observer's meridian (north-south line). It's a straightforward yet effective technique that has been used for centuries by sailors and navigators to determine their position at sea.

A high-quality print of this slim fit tank-top will turn heads. Bystanders won't be disappointed - the racerback cut looks good on any woman's shoulders.

.: Made with extra light fabric (60% combed, ring-spun cotton and 40% polyester: 4 oz/yd² (135 g/m²)) this racerback tank is supremely lightweight and an excellent choice for the active lifestyle.
.: The classic fit along make the tank a comfortable choice under high performance while the scooped neckline brings a sporty touch to the whole outfit.
.: For a completely scratch-free experience, all tanks come with a tear-away label for unhindered performance on a daily basis.