Typical Aussie Skiff mainsheet system. Popular on skiffs and other dinghies up to 5.5m (18ft) in length. 3:1 end-boom purchase, commonly fixed to a bridle at the transom, with sheeting direct from the boom to facilitate 'speedie' sheeting-in.
MWL = 325kg (715 lb)
Max Line Size = 9mm (5/16")
VARIATIONS: On boats up to 5m (16ft), such as 49ers and 16' skiffs, Series 30 ball bearing blocks are popular.


Dinghy 4:1 system utilising a traveller car to provide improved sail trim, and ratchet block on swivelling cam base in centre of boat for positive cleating from any angle.
MWL = 325kg (715 lb)
Max Line Size = 9mm (5/16")
VARIATIONS: Increase purchase as required by upgrading the rear boom, and traveller blocks eg. to double and double & becket for 6:1 etc.

Mainsheet 1 Diagram Backstay

Mainsheet 1 Diagram

Mainsheet 2 Diagram Backstay

Mainsheet 2 Diagram

Mainsheet #3

4:1 system with MWL of 800kg (1760 lb) making it suitable for yachts to 11m (36ft) in length. If operating near full MWL, light sheet winches are needed to hold the approx 200kg (440 lb) line load.
VARIATIONS: Replace Series 55 Orbit Blocks™ with Series 70 for yachts to 12m (40ft) in length.

Mainsheet #4

8:1 Internal/External system popular on high performance off-the-beach catamarans such as the A-Class. Series 20 blocks and 4mm (5/32") Spectra core ensure maximum load capacity with absolutely minimum weight. Internal feature keeps under boom access clear, and the 8mm (5/16") tail will make sure you still have some skin on your hands at the end of the race.

Mainsheet 3 Diagram Backstay

Mainsheet 3 Diagram

Mainsheet 4 Diagram Backstay

Mainsheet 4 Diagram

Mainsheet #5

Standard 6:1 mainsheet system for sheeting from traveller. Popular on off-the-beach catamarans, sports boats and trailerables.
MWL = 500kg (1100 lb)
Max Line Size = 10mm (3/8")
VARIATIONS: Replace boom block with RF40301 Series 40 Orbit Block™ for lower profile system (the only way to go on Hobie 16's. More rake = more height to windward!)

Mainsheet #6

Simple 4:1 cruising mainsheet system suitable for yachts to 10m (33ft) in length, 10mm (3/8") line capacity for ease of handling. Due to hand sheeting and cleating, MWL of 820kg (1800 lb) is rarely tested (will be totally reliable for many years of sailing).
VARIATIONS: Use Series 40 or 50 All Purpose blocks for a durable, virtually maintenance free system. MWL capacity's are more than you can handle, making desired line size the key selection criteria.

Mainsheet 5 Diagram Backstay

Mainsheet 5 Diagram

Mainsheet 6 Diagram Backstay

Mainsheet 6 Diagram

Mainsheet #7

Off-the-shelf two-speed racing mainsheet system (3:1 coarse, 6:1 fine) suitable for yachts and sportsboats to 11m (36ft). Pull on both sheets for quick adjustment, one sheet for fine tune.
MWL = 800kg (1760 lb)
Max Line Size = 12mm (1/2")
VARIATIONS: Replace RF72700 with RF72900 for yachts up to 12m (40ft).

Mainsheet #8

3:1 Course tune provides quick response, whilst 21:1 fine tune gives all the power you could need on performance boats to 9m (30ft). Internal fine tune, cleated from boom, ensures a clear cockpit.
MWL = 500kg (1100 lb)
Max Line Size = 10mm (3/8") coarse, 8mm (5/16") fine
VARIATIONS: Real heroes (who think they're actually skiff sailors) sheet directly from the ratchet block on the boom for ultra quick sheeting when turning the corners.

Mainsheet 7 Diagram Backstay

Mainsheet 7 Diagram

Mainsheet 8 Diagram Backstay

Mainsheet 8 Diagram

Mainsheet #9

Grand Prix racing system, popular on mid-size IMS boats, providing 4-6:1 coarse tune with 24-36:1 fine tune.
Fine tune trimmed from either side of cockpit, whilst coarse leads from a ratchet block on swivel base in the centre of the boat. Actual mechanical advantage, ie. 4 or 6 to one, for coarse tune, is dependant on position of forward boom blocks.
MWL = 1250kg (2760 lb)
Max Line Size = 10mm (3/8") coarse, 8mm (5/16") fine

Mainsheet #10

Basic 4:1 cruiser/racer system that provides real “grunt” [1500kg (3300lb) MWL], leech control via traveller mount, and requires only one winch to match a max line load of up to 400kg (880lb).

Max line size: A very comfortable 14mm (9/16”).

Mainsheet 9 Diagram Backstay

Mainsheet 9 Diagram

Mainsheet 10 Diagram Backstay

Mainsheet 10 Diagram

Mainsheet #11

The 'simplest' keel boat system, 2:1 purchase allows fast trimming. This system suits Racer/Cruisers to 12m (40ft), but the format is popular on much larger yachts as well.
MWL = 1000kg (2200 lb)
Max Line Size = 12mm (1/2")
VARIATIONS: To reduce sheet load, increase purchase to 4:1 by changing car block to an RF64202 double Series 60 and add an RF74100 Series 75 at the rear of the boom. (similar arrangement to System #9)


Mainsheet #12

Powerful and compact two speed racing mainsheet system.  The 6:1 coarse tune provides rapid sheeting while the 24:1 fine tune provides all the power you will ever need.  The single take off point makes the system ideal for mounting on traveller cars or central mounted positions.  An ideal system for sports boats and trailerable multihulls.
MWL 750kg (1650lb)
Max Line Size = 10mm (3/8”) coarse, 9mm (5/16”) fine
VARIATIONS: Splice the coarse and fine tune tails together so you can remain on the rail while gathering the required sheet.

Mainsheet 11 Diagram Backstay

Mainsheet 11 Diagram

Mainsheet 12 Diagram Backstay

Mainsheet 12 Diagram

Mainsheet #13

Powerful 9:1 system popular with large off-the-beach catamarans and trailerable multihulls where constant sheeting is required.
MWL 750kg (1650lb)
Max Line Size = 10mm (3/8”)
VARIATIONS: Upgrade to RC1221 car for more powerful traveller controls. Increase mainsheet purchase even more to 10:1 by changing RF45201 to RF45211, add an RF45101 hanging from the RF55410 (lashed through the hollow hub)and dead end at the becket on the RF45211.

Blocks with numbered sheaves are placed so sheaves are one behind the other and the front sheave is #1, second from the front is #2, etc. The bottom block (RF56330B ) is positioned with its sheaves side by side with the cleat facing toward you. The cleat side of each sheave is indicated with an ‘F’.

Mainsheet 13 Diagram Backstay

Mainsheet 13 Diagram
*Systems depicted on this website and their application to certain types and sizes of craft are SUGGESTED only. Conventional rig sizes, sail plans and displacments are assumed, and suitability for actual application should be checked with the appropriate yacht designer, naval architect or rigger as required.