The vertical fine structure statistics in the northwest Atlantic (midocean dynamics experiment area) have been studied by using the Woods Hole Oceanographic Institution/Brown CTD (conductivity, temperature, and depth). Five depth intervals including water masses representative of the entire water column have been subjected to spectral analysis of the temperature fine structure. All intervals show a similar power law dependence upon vertical wave number of -2.5, although spectral levels vary by more than a factor of 1000, whereas differences of only a factor of 2 exist on estimated vertical displacement spectra. Results are not inconsistent with the supposition that internal waves are responsible for much of the variability. On scales smaller than 10 m in the main thermocline features with the characteristic signature of sheets and layers begin to appear.