A method for estimating the dynamic depth variation along a maneuverable towed array using optical fiber hydrophones is proposed. The method utilizes the low-frequency components of the hydrophone signal which are typically high-pass filtered to suppress the adverse impact of hydrostatic pressure. Experimental depth data using a 32-element towed array in a lake agree well with measurements from commercial depth sensors. The temporal evolutions of the array shape in the vertical plane at towing speeds of 4 and 8 knots are also obtained.