Today we will take some time to work on roll tacks. We may move pairs around a little to try some things out.
Observations:
-synchronize rolling
-switch jib tack to tack without luffing
-roll later
-work on mainsail trim throughout tack
–tight in, then ease, then in…. after flatten, “re-adjust” main trim for one more push.

Timing of Roll
One of the biggest differences between a good roll tack and a great roll tack is the timing of the roll.  The vast majority of sailors tend to roll a 420 or FJ too early.  Unless it is very windy, rolling the second the jib backwinds is not ideal for effective tacks.  Many sailors get in a crunch, or get really excited, and roll before the boat is ready.  It’s natural to think that the faster you start your roll, the faster the tack is.  However, by rolling too early, you will get less help from the sails to turn the boat, and will actually steer the boat down with your weight while turning up with the tiller.  This creates a lot of friction with the rudder and the water, and you will have to steer much more to turn through the wind, slowing your boat down.  Additionally, backwinding the jib helps the boat turn during a tack significantly.  Thus, the longer you allow the jib to backwind, the less rudder you will have to use to steer through a tack.
As a general rule of thumb, you want to wait till the boat is at or just past head to wind before rolling the boat.  Waiting until this point will allow you to use less rudder, and will also allow you to use the wind to help roll over the boat.  If you go earlier, you will roll the boat against the face of the wind, forcing you to use much more effort to roll the boat over.
There is no exact time to wait before rolling the boat over, and it will change depending on the wind.  For example, in light air, you want to wait a relatively long time before rolling over the boat, as it will take longer for the sails to help you steer through the wind.  If it is really windy, you may want to cross sides quickly, as soon as the jib backwinds.  As soon as both sailors are hiking, you should not roll at all, especially in the FJ.  Instead, you should still use the sails to keep power in the boat the entire time, and simply switch sides and start hiking, when the jib backwinds.

Coordinating the Roll/Hitting the Rail at the Same Time:
A simple thing you can do to improve your roll tacks is having both the skipper and crew roll and flatten at the same time.  Anyone would agree that the more weight you apply to the windward rail, the easier it is to roll the boat over.  As an example, let’s say both the skipper and crew each weigh 130 lbs.  If the skipper stands on a scale alone, that’s the weight it will read.  Likewise, if the crew gets on the scale after the skipper, it will also say 130 lbs.  However, when both are on the scale at the same time, the scale will read 260 lbs.  The same principles in this example are directly applicable to rolling and flattening a boat.  If you roll or flatten at different times, the rail will feel 130 lbs. on it twice, instead of 260 lbs. at once.

Furthermore, you will increase the weight the rail experiences by getting your butt off the rail, and landing hard on the rail during the roll (both skipper and crew).  If you weigh 130 lbs. on a scale, and you jump up and down on it, the scale will say that you weigh quite a bit more than you do in actuality.  Thus, by having both the skipper and crew roll using this method, AND at the same time, that 260 lb. number can increase exponentially for two 130 lb. sailors.

The Jib:
Keeping the jib full the entire way through the tack is imperative for maintaining speed and power through a tack.  So often you see a crew release the jib sheet too early, leaving a gap between the backwind and the fill on the other side, where the jib luffs.  This disrupts the flow over the sail, and it will take a few additional moments to refill.  This will cause the boat to slow down and slide sideways.

To correct this, at the last moment prior to the jib starting to luff, pull hard on the primary sheet.  This will cause the jib to backwind much faster, and help start turning the boat earlier.  Hold the jib in a backwinded position until you start moving to the other side of the boat.  As you cross, snap the jib in on the other side with the new primary sheet.  If you execute this with a quick motion and correct timing, the jib will pop full without luffing for even the slightest instant.  The trick to this is waiting longer, and maintaining pressure on the clew of the jib with the jib sheets the entire way through the tack.  Thus, when you let go of the primary sheet, all of the slack needs to be out of the new sheet to continue to place tension on the clew.

The Main and the Flatten:
The final piece of a great roll tack (and the most difficult), is the movement of the mainsail following the roll, and through the flatten.  At the moment of the roll, you should have the mainsheet trimmed in as hard as possible.
As you cross sides (at the peak of the roll), you should have your main eased to a beam reach.  You do this to more effectively control the flatten of your boat, and because your apparent wind has shifted back, facing the side of the boat.  If you try to flatten the boat with the sail all the way in, it is extremely difficult and ineffective, as you are flattening against a sail that is full of wind.  By dumping the main, you can generate a much faster and more powerful flatten of the boat.  Also, at the peak of a roll, your boat actually comes to a complete stop for an instant before accelerating.  At this point, your apparent wind moves back, pointing directly at the side of your boat.  If your sail is in all the way at this point, your boat will slide sideways instead of moving forward.

Now, it is not enough to simply ease the sail.  If that is all you do, the boat would flatten really fast, but would not generate much power from the sails movement from a heeled to vertical angle.  A roll tack is fast because of power generated from both the centerboard’s and mainsail’s movement against one another through the water and wind respectively.  Thus, once the boat starts to transition back downward from a peak roll, the mainsail needs to start coming in.  The main should come back to its normal upwind trim at the exact point where the boat is flat again.  This part takes a lot of practice, but is worth it in the end!

Quick reference guide of the Do’s and Don’ts of great roll tacks:

Do:
– Steer with your sails (trim main/backwind jib)
– Keep the boat flat during the turn before the roll
– Roll later (after the jib starts to turn the boat)
– Roll at the same time
– Keep the jib full the entire time
– Ease the sails during the peak of the tack
– Trim the main in again as you flatten
– Straighten the rudder before you flatten

Don’t:
– Steer by healing the boat to leeward before the tack
– Roll too early
– Have the skipper and crew roll at different times
– Let the jib luff at all
– Keep the sails (especially the main) trimmed in while you flatten.
– Flatten with the rudder at an angle