CSIR-National Institute of Oceanography (CSIR-NIO) conducted a comprehensive Rapid Environmental Impact Assessment for the proposed 1 GW offshore wind farm in the Gulf of Khambhat, off Gujarat's Jafrabad coast, on behalf of the National Institute of Wind Energy (NIWE). The study established baseline environmental conditions across 400 sq. km, covering bathymetry, water quality, plankton, benthos, fisheries, marine mammals, and socio-economics, with water depths of 8–18 meters and two layout options (162×6.2 MW or 125×8.0 MW turbines). Baseline findings indicate low benthic diversity, high turbidity, elevated trace metal concentrations, and the presence of protected marine mammals (dolphins, whales, Olive Ridley turtles) and migratory birds. Advanced numerical modelling assessed wave, tide, current, sediment transport, noise, and wind wake impacts, predicting marginal bed level changes (±0.08m) and low-frequency noise restricted to 3.1 km from the site. Anticipated impacts include temporary habitat loss, underwater noise, bird collision risks, and fishing restrictions during construction, while operational benefits include renewable energy generation (2238 GWh/year) and socio-economic development. Mitigation measures include bubble curtains for noise reduction, marine mammal observers, orange turbine tip painting, and a comprehensive Marine Environmental Management Plan (MEMP) with a ₹490 Lakhs budget. The report concludes that with proper management, the project will contribute significantly to India's clean energy transition while minimizing environmental harm.