  KRAKEL is seldom used and tends to not be kept up-to-date.</li>
    </ul>
    <h2>Group II: Basic Plotting Routines:</h2>
    <ul style="font-family: monospace;">
      <li>&nbsp; PLOTSSP&nbsp;&nbsp; Plots the sound speed profile.</li>
      <li>&nbsp; PLOTMODE&nbsp; Plots selected modes.</li>
      <li>&nbsp; PLOTGRN&nbsp;&nbsp; Plots the Green's funtion for the
        depth separated wave equation for a particular source/receiver
        combination.</li>
      <li>&nbsp; PLOTTRI&nbsp;&nbsp; Plots the 