On 1-Apr-2005, "BCITORGB" wrote:

Sorry to disappoint, sailors call them sheets.

Nope - TnT is right - they are lines. Sheets are specific
types of lines - they are attached to the clew of a sail and
are used to control the sail. Guys are attached to the tack
of a sail and halyards are attached to the heads of sails.
This terminology for triangular sails - rectangular (or more
generally, four sided) sails use slightly different names.

There's lots of other lines too.

Mike