A novel ultraviolet-visible-near infrared imaging spectral system in air has been demonstrated to provide an effective instrument to measure the environment and pollution of the ocean along the coastal area. Based on the characteristics of the targets, different parameters of the performance of the system have been proposed. The Dyson imaging spectrometer was chosen to satisfy the requirements of the signal-to-noise ratio and the high optical performance. The Dyson spectrometer has not been widely applied in the engineering field because of its structural limitations. To solve this problem, the distances amongst the slit, the imaging plane, and the optical elements were increased to modify the traditional shape of the spectrometer. Therefore, perfect aberration eliminated conditions of the advanced system were obtained through analysis and addition of lenses. The advanced Dyson spectrometer presents excellent design features with an NA of 0.278 in the range of 320-1 000 nm. The Modulation Transfer Functions (MTFs) in all fields of views and all wavebands are larger than 0.5 at the Nyquist frequency 38.5 lp/mm of the detector. The prototype has a spectral resolution of 3.375 nm, satisfying the design requirement. This new spectrometer is more convenient and effective for coastal ocean observation.