Double-pulse laser induced breakdown spectroscopy (LIBS) measurements in water with up to 600 bar and 400 mJ each pulse were done to select laser parameters which promote optimized spectral line emission from plasma even at elevated pressures, where line broadening until loss of the most spectral information can occur. Optical emission spectroscopy, using a Czerny-Turner spectrometer, has been applied to investigate the dependence of the emitted radiation on laser parameters and hydrostatic pressure. It has been found, that higher laser pulse energies, especially with high water pressure, can also have an adverse effect on the measured spectrum. The spectral data was measured with an Roper Acton Spectra Pro 500i with connected PI-MAX2 camera. All data is available in internal spe format and as converted tif files. A metdata file with all relevant parameters is provided in xml format.