To provide a trim operation wire structure for a small surface boat with an improved operability.

A trim operation lever returns a nozzle for adjusting a jet direction of jet water to a normal direction by swinging the nozzle downward and releasing a grip. A trim operation wire 22 connected to the trim operation lever connects one end of a thin and easily bendable drawing wire 53 to the trim operation lever. The trim operation wire 22 further connects the other end of the drawing wire 53 via a push/draw converter 56 to one end of a thick and hardly bendable pushing wire 57. The push/pull converter is arranged on the boat right below or a bow 24a side of a steering handle 14. The length of the wire between the push/draw converter and the trim operation lever can be shortened, while the pushing wire can be lengthened. As a result, even when the thin and easily bendable wire is bent at several points, a sliding resistance of an inner wire of the drawing wire is kept small to improve the operability.