Ojha, M., Sen, M.K. and Sain, K., 2016. Use of split spread configuration of marine multichannel seismic data in full waveform inversion, Krishna-~Godavari basin, India. Journal of Seismic Exploration, 25: 359-373. Estimation of hydrate saturation from seismic reflection data is the primary goal of a gas hydrate exploration program. This requires higher resolution velocity models than can be obtained from standard traveltime tomography. Here, we employ an acoustic full waveform inversion (FWI) in frequency domain with a fixed background density to resolve for fine scale velocity structure of gas hydrate bearing sediments in Krishna Godavari offshore basin of eastern India. Conventional multichannel surface seismic data were acquired in 2010 using 360 channels with 12.5 m receiver interval, 25 m shot spacing and 100 m near offset for the investigation of gas hydrate in this region. We make use of moderate offset conventional end-on multichannel seismic data that are transformed to split spread configuration using reciprocity for use in our FWI. Data redundancy in split-spread configuration provides faster convergence and better resolution in our inversion resulting in a geologically meaningful velocity model. We make use of a smoothed interval velocity model derived from root mean square (RMS) velocity as an initial model and carried out inversion for fourteen frequencies in the range of 8 to 21 Hz at 1 Hz interval. Our results demonstrate that the split-spread dataset is able to resolve subsurface features much better than the conventional end-on data. For example, we notice marked improvement in identification of the free gas layer below the hydrate bearing sediments and many structural features like faults are conspicuous in the final image.