The extrusion's flat backside aerodynamically induces the laminar flow to attach more closely to the luff grooves. This shape coupled with the closely spaced luff grooves (patented) results in excellent aerodynamics on either tack.

The PROFURL extrusion makes airflow reattachment effective at distance "d" for maximum performance.

The competitions round extrusion makes airflow reattachment effective at distance D

Minimizing The Luff Tension When Reefing (patented)

The longitudinal grooves on the extrusion are located where the pressure of the reefed sail is at a maximum, and helps to pull the sail evenly for reefing during the first turn.

PROFURL's power is derived from its free rotation when under load which means if necessary, the sail may be flattened by winching the furling line. This means safer reefing because there is no flogging sail or flailing sheets which endanger equipment and crew. This feature can be particularly useful when coming into the wind. As apparent wind speed increases the sail can be flattened without easing the sheets.

Furling Line Safety

The stainless steel ring around the drum guards against the furling line jumping off the drum if the line lead is too high. The guard also serves to prevent sheets or other running rigging from snagging the arms.

Furling line block at good position.

Furling line block at wrong position.

PROFURL reefing systems with the "I" option have an integrated cylinder which extends upward from the drum mechanism. This enables the drum to be mounted at deck level with the turnbuckle inserted into the cylinder; this option allows for maximum luff length preferred by racers.

The adjustment and servicing of the turnbuckle is made easy by simply removing the cylinder connectors and sliding the mechanism and cylinder up the extrusion column.




ADJUSTABLE DRUM HEIGHT
Fitting with long link plates (LL)

By mounting the drum mechanism on long link plates several useful cruising features result:
- makes access to anchors and ground tackle easier
- raises the foot of the sail off the deck providing visibility forward
- eliminates loading the sail with boarding seas
- eliminates sail chafe by pulpit and lifelines
- allows immediate and easy turnbuckle inspection