Buoy for marine surveys. At least some of the illustrated embodiments are a buoy including an elongated main body and a mast system coupled to the elongated main body. The mast system includes: a forward mast; an aft mast; a spanning portion coupled between a distal end of the forward mast and a distal end of the aft mast; and an aperture defined at least in part by the main body, forward mast, aft mast, and spanning portion. The buoy is configured to float in water such that the water level intersects the forward mast and aft mast, the elongated body is submerged, and the spanning portion resides above the water level.