A "nautical theme" refers to a style or design that is inspired by the sea or the ocean. It typically includes elements such as boats, seashells, ropes, or anchors to create a maritime atmosphere. Full definition
Everywhere I looked, there were colors like bright coral and navy blue with nautical themed motifs being a dominant feature in the little girl's section. (thefashionablehousewife.com)
The plaid bedding brings sophistication to the subtle nautical theme in this boy's bedroom, while the eclectic map wallpaper ties all the colors together. (hgtv.com)