Abstract A 50 mGal gravity minimum and a 200 nT total magnetic intensity anomaly in the northern Red Sea shelf near the port of Safaga and a 250 nT total intensity anomaly across the Brothers Island indicate a more advanced degree of oceanization of the Red Sea crust than proposed from the results of the latest seismic studies in the same area. The interpretation of this gravity and magnetic anomalies reveals and extremely thinned continental crust which transforms to a mixed continental-oceanic crust some 50 km from the coast line. This mixed crust is found to contain segregated basaltic bodies, normally and reversely magnetized by the ambient Earth's magnetic field. The magnetic anomaly over the Brothers Island is interpreted as related to a short 4 Ma old spreading axis. A review of the results of this investigation together with previous studies suggests three modes for the emplacement of the oceanic part of the Red Sea crust in the Egyptian Red Sea shelf. The calculated crustal model at the offshore Safaga is compared with refraction based models across Saudi Arabia and the western Atlantic.