Debrief notes as promised as we were late finishing after the late breeze;
The day particularly tested team’s transitions between drift->trundle and trundle->drift. Recognising ands acting on these transitions is vital . Lets consider ‘drift’ is 0-4kn wind speed, sub 4kn boat speed and ‘trundle’ is 5-7kn wind speed and 5-6 boat speed (also know as the lighter end of underpowered mode)
Drift
In drift mode we have weight a long way forward with bow corner deep in the water to raise the stern reducing wetted area. Invariably this involves crews in front of the mast. We might also heel to leeward to further reduce wetted area and help fill sails. A hull trimmed forward like this will make a T foil trimmed fully on fairly neutral, ideal for very low speeds were it is not working effectively.
Upwind we will have kickers slack controlling leach by mainsheet alone, if the leach still hooks (Usagi) consider adding cunno (that looked like it worked) & slackening battens, maybe even adding uppers tension. We need to help the air exhaust, giving us full control of the leach via the mainsheet.
drift->trundle
As we accelerate through about 5kn boat speed the T-foil can start to work for us. Also the ‘sticky’ of the wetted area is broken. So there is no need for the bow corner deep plus the T foil is now pushing the bow down. Therefore the movement of righting weight outwards is a diagonal one, backwards. Move back until the bow corner is about level with the water surface. This might involve the crew moving from amidships in front of the mast to the racks in line with the shrouds or the helm moving back in along the racks in a high wiring mode. Beware of moving out and back to far ands too fast at this stage flow over the foil might be fragile and being over zealous might break flow over foils and sails and stop you dead.
As we accelerate the aim is to pull the boat square upright (presuming it started as heeled in drift/acceleration mode) for the foil to properly work for us.
The hull heel, hull trim & leach control of this acceleration phase is very delicate and needs practice to really get the feel of how to most effectively accelerate into the different form of sailing.
trundle->drift
Similar in reverse. In both drift and trundle modes as a rule you wont go much slower if you have your weight too far forward but you will go A LOT slower if you have weight to far back. As you decelerate in a lull the combination of low hull speed and no foil lift will sink the transom stopping you dead if you don’t move forwards quickly.
Mainsheet
I prefer to hold the mainsheet myself when the crew goes onto the bow in drift-trundle mode as I think one person alone can coordinate it better (easier communication between heel, steering and mainsheet trim) and it is easy enough to do in light winds. (Apologies crews union).
If crews do control the mainsheet in light winds very good communication is necessary to save choking the leach too early in the acceleration phase, thereby never accelerating.
Consider ease of trimming and ease of vision of leach. E-Numb3rs - At one point Sarah was trimming mainsail from under the ratchet (little vision, awkward dynamics and no feel for the boat there) whist Phil was wiring. I suggest you either swap your positions or swap the mainsheet to Phil.
Downwind T foil
As a rule keep it hard on until you get scared. As the bow goes down in increasing breeze walk ALL the way to the (very) back progressively until neither of you can go any further. If you are still afraid start to ease it. In flat water at QM for example you will keep it fully on much longer than you might in waves.
Downwind, before you have enough speed for the foil to work effectively you might match RS800 speed but you will need to do bigger angles to achieve it. After you have enough wind & speed for the T-foil to work effectively your goal is to still be a similar speed to RS800s but this time at a lower angle. This is due to lighter boats, lighter sailors, and an effective T-foil compounding that lightness enabling to keep the boat planning at a lower angle - downwind we are trying to sail as low as possible whilst still planning.
On E-Numb3r’s light wind tight twinning reach they initially had no T foil and were 1.5 wiring with the bow up. Phil pulled the T foil on hard the bow ‘bit’ down, the transom lifted and Phil immediatelty had to get his full weight outboard, then 2 wiring. So it powered them up. (If you need to point higher let some off again) .
In gybes, in trapezing conditions with the T-foil fully on, as you move forward to cross the boat the boat will steer around the bow with the transom feeling pretty light. (This may be worse for T-foils rather than Ronin’s ‘+’foil due to the length of leverage that the lifting surface is below the hull so suggests Jo Richards re his N12 design). This can feel can feel precarious and as it gets windy enough to upset you consider letting the foil of a bit in the gybes. Beware of letting it all the way off as in ‘sea anchor’ mode it will slow you down considerably loading up the main to give you a whammy coming out of the gybe.
If you are not sure how windy it is re T-foil position before a hoist have it in a cautiously off position before the hoist then pull it back on as much as you dare asfter you are settled with the kite filling and wiring.
Tacking - keep mainsheet fully in when entering the tack, it will;
1) Help turn the boat into the wind (therby helping getting you through a tack when the wind is up)
2) Keep the power on driving you forwards all the way to head to wind
Gybing battens – if you are having trouble flicking them after the gybe (Ronin) after an attempt give up and pull the cunno on to do it, easy. Better still, anticipate the problem and pull it on before the gybe. Maybe ease again afterwards. You wouldn’t lose much (or anything?) if you left it on and it would be much less distraction having battens going easily.
Usagi - your jib looked full after the wind increased, consider lowering the sheeting angle. You might have had it a bit too eased.
Usagi & E-Numb3rs might consider coarse adjustment on their trap gear of about 10-20cm (say 15cm) on the strings above the cleat. This enables you to;
1) go a bit higher in the light (bum should we well clear of rack when very light). Hooking on early and high in the very light will enable to move more smoothly and finer amounts than not being hooked on, provided you keep your footing and don’t swing around!
2) go a bit lower in the windy when right at the back of the boat. E.g. when over stood leeward mark.
3) mostly stay near the mid length of adjustment string beneath the cleat which is easier than being very close or very far away from where your hand grabs it.
Usagi- your adjusters did not look like they gave you the option to get low enough, especially after you move back.
Trapezing low when bouncing downwind will make your stance more stabe not less.
