Judging laylines or crossing situations not your best skill? Fear not, the AccuTack is a simple reference tool that will be your guide to better assessing these situations saving you those valuable extra boat lengths, or quite possibly, saving you a call to your insurance broker. This pair of port and starboard 11 in x 7 in AccuTack appliques are made of a durable heavy weight Mylar. The 3M self-adhesive backing adheres securely to non-skid decks as well as painted surfaces. Full instructions for use and application are included.