Conventional large cam cleats are mounted on the gunwhales
just aft of the chainplates and behind the twinning lines (described later).
The twinners are used to pull the guy down into these gunwhale cleats, which
are then used to hold the spinnaker pole back on runs and broad reaches.
The continuous sheets themselves are made from tapered 4mm /
6mm white Spectra, and pass through blocks mounted at the aft end of the
cockpit, before being led forward through turning blocks mounted under the side
decks, just forward of the console. These forward blocks were originally
ratchet blocks, but these were found to be unnecessary (Mike having strong
arms!), and replaced with standard 25mm ball blocks.
In front of the blocks are large cam cleats, fitted with
Harken roller-type front fairleads. These fairleads were a later addition, and
enable the sheets to be pulled easily from funny side angles (such as when the
helm is steering the spinnaker through a gybe).
The spinnaker sheet system on 2663 is particularly neat
compared to other Fifteens I have sailed, as everything is tucked away beneath
the side decks - it is not uncommon to see boats with the sheets running along
the top of the decks where they (and the turning blocks and cleats) are
constantly being sat on by the helm. As well as being uncomfortable this can be
a major irritation for the crew when running, as the helm sitting on the sheet
prevents it being adjusted.