In Mast / Behind Mast Reefing Mainsails


Jeckells have been manufacturing ITM (In The Mast) mainsails since the idea was first tested. There have been considerable technological improvements since its conception and we have perfected our ITM mainsail design in order to provide excellent performance on all points of sailing whether partially or fully unfurled.


  • All Cruising sails are Guaranteed for Five
  • We listen to your needs
  • Over 60,000 sail designs on record
  • Heavy Duty, Race or Charter Specification
  • All sails are computer designed and laser cut
  • Sail numbers and insignia are included
  • Sails bags are supplied as standard
  • Continued support from our unique after sales service



One of the problems with ITM mainsails is the loss of sail area and consequently reduced performance. To counteract this, we have developed a sail with vertical battens which enables the sail to be approximately 15% larger, so when combined with improved aerodynamics, increased performance and a better balance are achieved.


  • UV resistant acrylic clew patch
  • Leech line
  • Clew block fitted to larger sails
  • Specially designed luff tape to ensure smooth furling and reefing