Prior to placing your order for your Tides Marine Track and Slide System, you must determine the size and style of the mast groove (width "A"and lip thickness "B"), or width of existing external track "F".
Tides will send you a set of measurement discs which were developed for this purpose (see below).
Each disc has a series of gauged studs which correspond to the most common mast groove configurations. The discs with numbered studs are for
determining slot lip thickness. Lettered discs are for determining slot width.