Rathmullan sailing school notes

Course Objective & Pre-requisites

To develop advanced boat handling and tuning skills, including a clear understanding of how sails and foils work together, preparing sailors to sail flat out in strong winds.

Pre-requisites:

  • Completed the **Improving Skills** certificate.
  • At least **20 hours** logged post-Improving Skills.
  • Confident sailing in strong winds.

Evaluation Focus:

  • Confident, controlled manoeuvres in strong winds.
  • Optimised sail setup for performance.
  • Application of speed and tuning techniques.

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Rigging, Tuning & Controls

Advanced performance starts ashore with precise setup and dynamic on-water adjustments.

Ashore: Rigging & Static Tuning

  • Full Rigging: Confidently rig any boat (dinghy, keelboat, cat) from trailer to water, including mast stepping, reefing, and furling systems.
  • Ropework: Demonstrate all prerequisite knots and splices.
  • Spreader Adjustments: Understand and explain how spreader length and angle affect mast bend and sail shape.
  • Mast Ram/Chocks: Know how to use mast ram or chocks to pre-bend the mast and position it correctly.

Afloat: Dynamic Controls

  • Sail Camber: Use Cunningham and Outhaul to change the depth and position of the sail's draft for power or depowering.
  • Leech Tension: Use the Kicker/Vang as a primary control (especially downwind) to manage leech twist and prevent overpowering.
  • Feedback Loop: Demonstrate using all primary and secondary rig controls to optimise performance in changing conditions, reading feedback from the boat.

Rig-any-Boat: Step-by-step Checklist

  1. Hull & Foils: Fit bungs; rudder/centreboard pins secure; bailers shut.
  2. Mast Stepping: Check shrouds/forestay clear; communicate “ready, lift, heel boat to you”; pin forestay/shrouds.
  3. Standing Rigging: Hand-tighten bottlescrews evenly both sides; sight mast is centred at partners.
  4. Running Rigging: Lead halyards, sheets, vang, cunningham, outhaul; test each to full travel.
  5. Sails: Hoist main (battens in), set outhaul/cunningham nominal; hoist jib, set lead marks to class baseline.
  6. Controls Check: Pull each control on/off; mark repeatable settings with tape/sharpie.
  7. Dock-Tune: Final safety check (PFDs, bungs, foils leash), then launch.

Success criteria: boat fully rigged without instructor input, all controls free-running, mast straight athwartships.

Primary Controls and Their Effects

How to Measure Mast Rake

  1. Hoist a tape on main halyard; lock at black band.
  2. Measure to transom edge (or top of gudgeon). Record.
  3. Target examples: Light longer rake; Medium class baseline; Heavy shorter rake.
  4. Adjust at forestay/bottle-screws in equal turns both sides; re-sight mast centre at partners.

Outcome: repeatable upwind balance (slight weather helm) across wind ranges.

How to Set Rig Tension

  1. Use a Loos gauge (if available) on shrouds; note class guides.
  2. No gauge? Pull leeward shroud on-beat: Light = goes slack; Med = just slack; Heavy = remains just firm.
  3. Adjust bottlescrews equally; re-check mast straight side-to-side.

Outcome: jib luff stable, pointing improved; forestay sag controlled per conditions.

Spreader Length & Sweep (Angle)

  1. Length: measure from mast side to shroud centre; match class baseline (± adjustments).
  2. Sweep: lay a straight batten across spreader tips; measure back to back edge of mast.
  3. More sweep = more prebend (flatter main); less sweep = fuller main. Change in small increments.

Outcome: mainsail luff curve matches mast bend in target wind range.

Mast Ram / Chocks (Partners)

  1. Upwind Power: remove chocks/ram aft to allow mast to sag slightly to leeward—adds depth.
  2. Depower/Pointing: push ram forward or add forward chocks to increase bend—flattens/leech opens.
  3. Reaching/Running: control leech with vang; keep mast supported to avoid over-bend creases.

Outcome: quick trim range without re-rigging between races.

Control Function When to Tension When to Ease
Cunningham / Downhaul Strong winds: depower, move draft forward, flatten sail. Light winds: maximise power, move draft aft, fuller sail.
Outhaul Controls lower-third shape and foot tension. Strong winds: flatten to reduce heel and depower. Light winds: ease to create deeper, more powerful camber.
Kicker / Vang Controls leech tension and boom when mainsheet is eased. Reaching/running: tighten to stop boom rise and limit twist. Upwind/light winds: ease to open leech and reduce drag.

Secondary (Standing Rigging) Controls

  • Spreader Length & Angle: Spreaders pre-bend and laterally support the mast. More sweep increases pre-bend to flatten the main in heavy air. Excess length risks inversion.
  • Mast Ram / Chocks: Pushing mast base forward increases bend (flattens main); allowing aft movement decreases bend (powers up main).
  • Sail Camber (Draft): Depth of curvature, controlled mainly by Cunningham and Outhaul. Aim for draft ~40% aft of luff in most conditions.
  • Leech Tension: Managed primarily by mainsheet (upwind) and vang (offwind). Too tight stalls; too loose spills power.

Rigging Competence

  • Mast Stepping: Communicate clearly. Check spreaders, shrouds, and forestay are clear and secured before lifting.
  • Reefing Systems: Practice slab (main) and roller (headsail) reefing on shore to ensure all lines run freely.
  • Spinnaker Rigging: For Kites & Wires graduates: correctly lead sheets/guys; practice hoists and douses across wind strengths.

Advanced Sailing Knowledge (Aerodynamics)

Understanding why the boat is fast is key to maintaining speed. Focus on how the mainsail and jib interact to increase lift, and how trim on one affects the other.

3.1 The Slot Effect

The jib accelerates air over its leeward side and feeds this faster flow through the slot between jib and main. This dramatically increases airflow over the mainsail's leeward side, boosting pressure differential and overall drive.

Maximising the Slot

  • Jib Lead: Position so leech twist is correct; the slot should be roughly parallel top-to-bottom.
  • Sheeting Angles: Sheet so the exit flow feeds cleanly onto the main. Too tight backwinds (stalls) the main; too loose loses the benefit.

3.2 Sail Trim Interaction

  • Jib on Main: A tightly sheeted jib pulls the bow down and can flatten the main by tightening airflow around the luff. In stronger winds, easing the jib slightly can power up the main by allowing cleaner cross-rig flow.
  • Main on Jib via Mast Bend: Heavy mainsheet tension (and vang) induces mast bend, flattening both sails—reducing power but maintaining control.

3.3 Optimising Hull, Spars & Sails within Class Rules

  • Hull: Fair and smooth below waterline; remove nicks; polish to a satin finish. Ensure weight and fittings comply with class rules.
  • Foils: True, smooth profiles with crisp trailing edges (not knife-sharp); align rudder/board to minimise helm drag.
  • Spars: Check straightness and fitting security; spreaders equal and symmetrical; traveler/boom ends free-running.
  • Sails: Class-legal measurements; mark repeatable trim references (vang, cunningham, outhaul) and jib lead holes.
  • Documentation: Keep a trim log: wind, sea state, settings, results. Change one thing at a time.

High-Performance Boat Handling

Achieve controlled, flat-out sailing, maximising speed and minimising loss of distance during manoeuvres.

1.1 Planing Setup and Control

Planing occurs when the hull lifts to reduce wetted surface and drag, letting speed exceed displacement limits.

Component Goal Control Method
Crew Weight Fore/aft: move aft to lift bow and reduce drag. In/out: maximise leverage to keep boat flat. Crew/helm move quickly and decisively with gusts and lulls.
Heel Maintain slight weather heel (1–5°) to reduce rudder drag and stand mast up. Helm uses small, smooth tiller inputs. Crew uses body weight/trapeze/hiking.
Sail Trim Main on with controlled twist; jib slot open with telltales flying 100%. Constant sheeting/feathering in gusts to keep boat flat and balanced.
Rudder Minimal input; rudder is a brake when moved. Track straight; use weight and sails for fine course changes. Feather in gusts, bear away in lulls.

Key concept – Balanced helm: Tiller pressure should be neutral or slightly weather helm, indicating efficient sail/foil balance.

1.2 Effective Roll Tacks

Use momentum and body roll to drive the sails through the wind with minimal speed loss.

  1. Preparation (old tack): Build speed; helm/crew forward and slightly to leeward with small weather heel.
  2. Initiation (head to wind): Helm snaps the turn with minimal rudder; crew crosses to new leeward to roll boat flat or slightly to windward.
  3. The roll: As bow passes through, crew sits out hard on new windward, forcing deep leeward roll; sheet in rapidly to pull sails onto new side.
  4. Exit (new tack): Helm straightens; trim for new course and adjust weight for speed and heel. The roll provides most of the turn.

Common errors: over-rudder (speed loss), late sheet, staying too far aft. Success: audible whoosh/acceleration on exit.

1.3 Effective Roll Gybes

Control the sail switch in strong winds and induce acceleration in light winds.

  1. Preparation: Weight slightly forward; sail deep. Crew holds mainsheet and takes tiller extension.
  2. Initiation: Helm turns smoothly; crew hauls main to centreline (or just past).
  3. The roll: As sail crosses, crew sits out hard on new windward to force sharp leeward heel—preventing rig slam and filling quickly.
  4. Exit: Helm straightens; ease main to broad reach trim. The righting moment from the roll creates acceleration.

Common errors: vang too tight (boom won’t cross), no roll on exit, bearing away too much after the flip.

1.4 Picking Up a Mooring (All Wind/Tide)

  1. Plan: Identify wind and tide dominant force. Approach on a close reach to the mooring’s leeward side.
  2. Approach: Control speed with sheets; feather to slow. Crew ready forward with hook/line; keep weight central.
  3. Final metres: Luff to bleed speed; stop head by the pickup. Crew lifts and secures to bow cleat through the ring (no wrists in bight).
  4. Settle: Ease sails, centreboard half, rudder down; double-check security.

Cross-tide: ferry-glide across the stream; strong tide, minimal sail—use current to drift onto buoy.

1.5 Approach, Come Alongside, Leave a Pier/Pontoon

  1. Setup: Fenders and lines ready; decide upwind or uptide side preferred (aim to approach into the stronger force).
  2. Approach: Beam/broad reach in; ease main early to decelerate; final approach nearly head-to-wind, crew ready to step (not jump).
  3. Alongside: Crew steps onto pontoon with bow line first, then stern line; secure; sails depowered immediately.
  4. Departure: Spring off: hold bow line, push stern out (or reverse if needed), sheet in and steer away under control.

In strong crosswind/tide: crab in with ferry-glide; never try to “turn in the last metre”—establish control early.

1.6 Tight Circular Course (Moderate Conditions)

Drill to develop coordination, heel control and fine steering.

  1. Set a small radius (~2–3 boat lengths). Sail continuous circles maintaining heel 0–5°.
  2. Use weight and sheet to steer; keep rudder movement minimal and smooth.
  3. Target constant speed: feather in gusts, bear away in lulls; trim continuously.

Success: wake clean, constant heel, no stalls; helm pressure stays light.

1.7 Follow the Leader (Moderate Conditions)

Develop anticipatory trim and steering.

  1. Leader makes smooth S-turns and speed changes on reach and beat.
  2. Followers maintain fixed gap without rudder overuse—use weight/trim to react.
  3. Rotate leaders every 2 minutes; debrief on wake cleanliness and control.

1.8 Rudderless on All Points (Moderate)

  1. Remove/secure tiller; start on beam reach.
  2. Turn up by sheeting in/heel leeward; turn down by easing/heel windward.
  3. Progress to close-hauled and broad reach; add centreboard height to amplify sail-steer.

Success: tack/gybe completed rudderless with control and minimal drift.

Boat Speed: Waves, Steering and the 5 Essentials

Speed is technique plus consistency. Use these drills to lock in fast habits.

2.1 Maximise Speed in Waves

  • Upwind: Feather in wave faces; bear slightly and sheet for punch over crests; keep boat flat.
  • Reach: Small S-turns to surf; trim main to keep telltales flowing; crew moves aft in surf.
  • Downwind: Chase dark patches; steer to stay on wave; ease vang to open leech and prevent rolling.

Drill: “3-wave sets” — call trim/steer actions for each of three consecutive waves, then repeat.

2.2 Optimum Course & Steering Technique

  • VMG focus: Sail the angle that gives best velocity made good, not just closest to wind.
  • Minimise rudder: Trim and weight first; tiller last. Every degree is drag.
  • Gust response: Head up in gusts (convert power to height), bear away in lulls (protect speed).

Drill: “Rudder cap” — helm keeps hand on tiller extension joint; must steer primarily with trim/weight.

2.3 Adapting the 5 Essentials

Light (0–8 kn)

  • Balance: bow down, minimal heel, smooth roll kinetics.
  • Sail set: full, draft aft; vang eased for twist.
  • Trim: constant micro-ease/trim to keep flow attached.
  • Course: sail lower for speed; avoid pinching.
  • Centreboard: slightly raised offwind.

Moderate (9–15 kn)

  • Balance: flat boat; hike proactively.
  • Sail set: baseline shape; vang engages on reaches.
  • Trim: positive sheet for height; react to gusts.
  • Course: VMG angles; smooth steering.
  • Centreboard: full upwind; adjust reaching.

Strong (16+ kn)

  • Balance: aggressive hike/trapeze; spill early.
  • Sail set: cunningham/outhaul on; vang to control leech.
  • Trim: ease in gusts to stay flat; quick re-trim.
  • Course: foot for speed; avoid excessive height.
  • Centreboard: slightly raised downwind to reduce trip.

Emergency & Safety Drills

Confidence and control in emergencies are essential. Practice the following until they are automatic.

4.1 Steering Without a Rudder

  • Sheeting: Main in hard rounds up (windward); easing bears away. Most effective on beam/broad reach.
  • Weight: Move to leeward to round up; to windward to bear away. Very effective on run/broad reach.
  • Centreboard: Raising increases sheeting effect; lowering adds stability.

4.2 High-Speed Man-Overboard (MOB)

  1. Stop: Call "MOB" and point; execute a swift stop (crash tack or bear-away/tack) to slow the boat.
  2. Turn: Set up on a close reach (~45° to wind) toward the casualty.
  3. Approach: Use fill-and-spill to control speed—sheet in to move, ease to slow; aim for zero forward speed at contact.
  4. Recovery: Make contact on leeward side; trim to keep boat close and avoid blowing over the casualty.

Figure-8 variant: reach away 4–6 boat lengths, tack, broad reach back to leeward of casualty, luff to stop with casualty at shrouds.

4.3 Capsize Recovery in High-Performance Boats

  • Avoid entrapment: Extra rigging increases risk—use any air pocket under hull to exit, check for crew/helm.
  • Spinnaker up: Release halyard and retrieve kite before righting to prevent drogue effect/inversion.

4.4 Emergency Stop: Heave-To

  1. Tack: Initiate a normal tack.
  2. Back the jib: Leave it sheeted on old side as you pass head to wind.
  3. Lock the helm: Tiller hard to leeward once slowed.
  4. Balance forces: Backed jib pushes leeward; main and rudder push windward—boat sits nearly stationary, drifting slowly.

4.5 Sailing Under Jib Only

  • Purpose: Simulate damaged main or heavy-wind safety mode.
  • Control: Expect heavy leeway and strong lee helm; effective on reach/run only.
  • Execution: Sit forward; use weight and jib sheeting aggressively to maintain course.

Ropework

Demonstrate all prerequisite ropework skills from previous levels.

Essential Knots

  • Figure-of-eight (stopper)
  • Bowline (non-slip loop)
  • Round Turn and Two Half Hitches (mooring/fenders)
  • Clove Hitch (temporary attachment, fenders)

Finishing & Care

  • Splicing/Whipping: Whip ends to prevent fray; understand basic splicing.
  • Coiling: Neatly coil and stow lines to prevent snags and ensure immediate use.

What's Next?

You can now describe how to continue sailing and record your progress in your logbook. You are now ready to try another SBSS Advanced Module, such as **Start Racing**, **Adventure Skills**, or **Kites & Wires**.

Assessment Checklist (Map to Objectives)