. The addition of an accurate pressure sensor to the inverted echo sounder (IES) has allowed for the development of a new method for calibrating the IES's acoustic travel time record, without the need for coincident CTD or XBT profiles. Using this method, the round trip travel time measurement of the IES can be calibrated into various dynamical quantities with better accuracy than was possible with previous methods. For a set of 4 IES records from the Newfoundland Basin the estimate of the accuracy of the geopotential height anomaly (integrated between 100 and 4000 db) calibrated from the IES measurements was reduced from 0.65 m 2 s Gamma2 to 0.52 m 2 s Gamma2 , which is a substantial reduction toward the intrinsic scatter of the geopotential height anomaly versus travel time relationship for this region (0.42 m 2 s Gamma2 ). The addition of the pressure sensor to the IES results in reduced errors, and eliminates the need for coincident CTD measurements. Moreover the pre...