Davis DockShockle 12 The Davis Instruments DockShockle is a simple and safe solution for reducing dangerous shock loads and minimizing stress on lines. Additionally, the DockShockle reduces chafe, resulting in longer lasting lines. You can use the DockShockle with all types of dock lines up to 34 in diameter. For braided or twisted lines, a pair of Mini-Line Grabbers are included for easy attachment. The Davis DockShockle is designed specifically for dock lines for smaller, lighter boats up to 4