Our Ride

Nacra Infusion MK2 outfitted with Ronstan Hardware and FSE Robline.

One of the most competitive F18 designs currently available, this boat is ideal for both endurance sailing and short-course racing.  The catamaran design allows for speeds unseen by traditional race boats, even those up to three times larger.

From Performance Sports, Inc: The Nacra Infusion is the only production catamaran that is made with infusion technology. This technique makes sure that weigh distribution in manufacture produces a much stiffer hull compared to conventional methods, and stiffness of hull produces extra performance in high level racing for many more years. The production of dagger boards and rudder blades is also new, being made in three dimensional shaped aluminum moulds using high compression to give Nacra F18 Infusion MK2 stiffer and stronger blades for high level racing. The Nacra Infusion features a wing mast that provides superb rig dynamics coupled with advanced sail design from Performance Sails.

Details:

Length	5.52m
Beam ( width)	2,60m
Mast Lenght	9,08m
Weight	180kg
Mainsail area	17m2
Jib area	3.45 / 4.15 m2
Asym. Spinaker	19 / 21 m2
# Trapeze	2 persons in trapeze

 

Boat Setup

Tramp Overview

The underside of our tramp is an organized mess, and here's how it works (see photos).  The idea behind all the bungee is that when the kite is down, the tack line sits tight to the front beam, tensioning the 1/8" bungees attached to the kite halyard/retrieval system.  This keeps the loose halyard from getting twisted behind spreaders while going upwind.  When you hoist, the tack line bungees go slack, allowing the retrieval line takeup to go slack, preventing that crease down the middle of the kite.  When using this system, it allows you to add an 18" retrieval tail at the kite clew, to clean up the sheets when not in use.  Not quite sure of the bungee length, but it should be snug when the kite is down, and semi-loose when hoisted.

Righting Line:

 

Tackline / Spinnaker:

Skipper Bungee:

Up F*cker:

 

Line Info

Important Notes!  All lengths are of finished lines.  When making your own sets, it's important to remember the extra lengths needed for proper splicing buries (before you start cutting!).  We use FSE Robline products for 99% of our rigging, only substituting Marlow Max in a few geeky areas where FSE does not make an equivalent product.  Marlow Max is a pain to track down, so 3mm Ocean 3000 can make a good substitute.

Mainsheet: 
24' Racing Sheet Pro 8mm
8'6" Ocean 3000 4mm
1' split tail of each

Spin Sheet:
43' Racing Sheet Pro 8mm
2' Ocean 3000 4mm

Downhaul:
36' Dinghy Control 3-4mm

Spin Halyard:
25' Marlow Sk78 Max 2.5mm
32' Racing Sheet 4-5mm
12' Ocean 3000 3mm

Tack Line:
12' Marlow Sk78 Max 2.5
5' Dinghy Control 4-5mm

General Tuning

(Nacra Infusion focused, but probably some good stuff for everyone else too)

This is a compilation of setup tricks and rig settings from a bunch of sources - the Nacra factory, Microwind experience, and learning from guys better than us.  Not guaranteed to be right, but it should help your boat speed along in the right direction.

Seating beams:

Hulls are pretty good out of the box, but seating the beams really stiffens the platform.  This can be a gross and messy job, so skip this part if you’re not comfortable with boat work.  Do one beam at a time!

1. 1. Ensure that the assembled platform is on a flat surface and the hulls are in line(measure the diagonals)
2. 2. Unbolt ONE of the beams, clean and wax the contact area with polish or mold release agent
3. 3. Lightly sand and clean the beam cradle of each hull
4. 4. Mask off the hulls and beams everywhere you don’t want stuff to drip, cover more than you think, it drips everywhere.
5. 5. Oil or release agent the beam bolts and hull threads.  Stuff the hull threads with modeling clay to prevent epoxy from oozing in
6. 6. Paint a thin layer of gel-coat or slightly thickened epoxy on each beam cradle, leaving room around the bolt holes
7. 7. Put the beam carefully back on and crank it down, cleaning any squeeze-out with acetone. 

Foils:

With properly balanced foils, the boat should track straight for a while under sail.  This is controlled by rudder toe in.

1. 1. With the beach wheels at the front beam, have someone sit on the bows to lift the sterns enough to drop the rudders
2. 2. Measuring at the bottom of the hull, the trailing edges should be 2mm further apart than the leading edges (at foil centerline)
3. 3. Adjust this angle by equally moving the rubber universal joints and resetting the set-screws

 

When turning, the helm should not be heavy to push or pull.  This is controlled by the rudder rake.  The measurement from the face of the black casting to the center of the adjustable eye screw gudgeon should be 22mm.  Be sure to crank on the set nut to remove wobble.

Most rudder and dagger trailing edges scream and wail at some speed.  Nobody knows the perfect fix.  The best ideas are to put a 45˚ bevel on one side of the edge with a file, or to sand the trailing edges between pinched fingers, getting it as fine as possible

Mast Rake:

This setting can affect the balance of the helm, and is adjustable according to wind strength.  Adjust this setting on the forestay chain plate.  To measure, tie a line to a trapeze wire and run it to the bow tang for the forestay bridle.  Pinch that spot on the line and move to the transom.  This length should fall on the upper screw of the rudder retainer spring.  When setting up for a nuclear day (20+ knots), drop the rig back so that the pinched spot falls on the lower screw.  Lighter teams can rake back slightly earlier, heavier teams slightly later.

Rig Tension:

Not super important.  Snug is good, and when sailing the leeward shroud will flop a little.  Too tight and the mast won’t rotate properly.

Diamond Wires and Spreader Rake:

Spreader rake is measured by placing a batten across the wires at the spreaders and measuring between the inside edge and the mast track.  50mm is the standard setting, +5mm for lighter teams, or -5mm for heavier teams.

Diamond tension is a major control which, in conjunction with the Cunningham and mast rotation, determines the power of the mainsail.  F18 rules allow adjustments between races, ALWAYS have a wrench on the water!  A rough estimate is that one full turn on the bolt increases tension by one number.  Your base setting will be when looking up the sail track, a small amount of pre-bend starts to show.  This should be at 37 on the black Loos gauge.  Max tension should not exceed 43, as any more flattens the sail too much.

Checking the diamond tension is done with the Cunningham, which should never be tough to trim.  If the downhaul is on hard and you’re overpowered, you need more diamond tension.  If lacking power while completely eased off, the diamonds are too tight.  Since both controls adjust the depth of the main by bending the mast, think of the diamond wires as the gross tune, and the Cunningham the fine tune.

Mainsail Notes:

Batten tension should be snug to take out wrinkles, but not tight enough to stretch the cloth.  If you have the option, heavier battens for the top four spots are good when it’s nuclear.  This doesn’t affect speed too much, but the sail inverts and does weird things without them.

Outhaul doesn’t change much.  It can be eased slightly for light air, sloppy waves, long distance downwinds, or heavier teams.  Trim on a little for the opposite of all that.

The Cunningham is a live control.  If the mainsheet has to be eased more than an arms length while going upwind, you need more downhaul.  Be preemptive and ready to ease in lulls or crank it in puffs.  Huge gains can always be made in these transitions.

Mast rotator ranges from the middle of the dagger trunk to the inside of the back beam.  As breeze builds, rotate the mast in accordingly.  Rough water can demand a deeper sail and in flat water, rotating in more helps with pointing.  Small adjustments go a long way.

Jib Notes:

In most conditions, the jib traveler sits on the second post from the end.  In heavy breeze or big waves, it can go out an inch or two - opposite for light air and flat water.

Tying a 60mm loop of spectra between the jib head and hook is a good idea, as it opens the slot a bit.  The jib downhaul may have to be lead around the spin pole to accommodate.

On the clew board, center hole is good for most conditions.  Bottom hole in really heavy breeze or confused waves to open the top and increase twist.  Use the top hole in very flat water and light-medium breeze.

Spinnaker Notes:

Luff tension should allow for a half hand twist when holding the luff tape.  A tight luff is very important as the breeze increases – make sure the halyard is hoisted all the way!

Upwind Settings:

 

Downwind Settings:

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