Mirror Class rules allow the mainsheet to be rigged so it comes to the helm from either the aft transom or from near the centre of the thwart (seat) or directly from the centre of the main boom. Traditionally Mirror dinghies had aft mainsheets with a 2:1 purchase. Since centre mainsheets have been allowed, they have become standard on new boats.
The UK MCA recommends that children are taught to sail on boats with a centre mainsheet as this is now the standard system on nearly all dinghies sailed in the UK (Optimist, Pico, Topper, 420, 29er,....). It allows children to move to, and from, Mirror dinghies without having to learn to tack in a different manner.
One disadvantage of these systems is that, in general, they constrain the space available for the crew between the kicking strap and the mainsheet when tacking and gybing. Options for giving more space are:
- Position the block on the boom aft of vertically over the block near the seat
- Move the kicking strap attachment point on the boom further forward
- Use a GNAV (strut) kicking strap.
Below are links to descriptions of the most common centre mainsheet systems. Within each system there are often further options for fittings or other equipment