One option is to consider a custom-made office wing chair. Because wing chairs aren't traditionally built for office comfort, look for a custom-made one or one that is designed specifically for office use. Drape a throw on it depicting antique globes, and the nautical office scene is set.
Cherry and birch are popular and timeless wood choices for nautical office chairs. An upholstered leather wooden captain's chair would set the nautical tone nicely. If you opt for a steel chair, look for nautical details such as curved arms, engraved designs and high backs.
Hand-paint the wooden or steel base white, and then paint an anchor on the first chair rung. This is an inexpensive way to liven up an old office chair and give it a nautical flair.
If you're going for a more rustic look, you still need to consider comfort and color. Have fun with patterned fabrics for seat cushions to soften the hard wooden chairs. Think ships, blue and white stripes, lighthouses, globes and anchors.