ORCV WS Race 2 — RBYC to Blairgowrie

Headline

A single starboard-tack jib reach down the eastern shore for ~2h40m, then a 1.5h beat west along the Sorrento shore into building breeze, building sea and a young adverse flood. The breeze roughly doubles during the race — set up for the finish conditions, not the start. Model agreement across all 10 GRIBs (ECMWF, GFS, ICON, ACCESS-VT, AIFS, WRF, PWE/PWG et al., run Thu 2 Jul 1937) is unusually tight — confidence is high. All times AEST, directions °M.

Timeline (optimal route)

• 0930 Start (RBYC) — TWD 251, 9–10 kt (g14), TWA 65 stbd, sea 0.5 m
• 0946 WS-1 Gate — 249, 10 kt (g15), TWA 74, 0.6 m
• 1100 Mid-bay, Mt Martha abeam — 236, 12–13 kt (g16), TWA 63–65, 0.9 m
• 1210 SB1 — 226, 14 kt (g16), beat begins, tacks ±36–40, 0.9 m
• 1226–39 SC21 / SC19 — 224, 15 kt (g16), beating, chop over the sands
• 1327–36 Sorrento 12 / 10 — 221, 17 kt (g22), ±38–44, 1.9–2.0 m
• 1341 Blairgowrie finish — 221, 17 kt (g22), 2.0 m

Optimal elapsed 4h10m, 32.3 nm sailed (30.7 nm rhumb). Boat speed 7.8–8.3 kt reaching, ~7.0–7.5 kt beating. Jib the whole way — no spinnaker leg.

Pressure & wind

A strong winter high (~1029–1030 hPa) ridging over the bay behind a departed front, gradient squeezing as the ridge builds. A cool, stable SW stream that builds all day rather than fading. No frontal passage — the 30° left shift is a steady trend, not an event.

• Speed: 9.5 kt at the gun → 12.5 kt by 1100 → 14 kt at SB1 → 17 kt at the finish. Gusts open from +3 to +5 kt, reaching 22 kt near the finish.
• Direction: 251°M backing steadily to 221°M — roughly 7–8°/hour left. This is the tactical backbone of the race.
• Ensemble: everything sits in the 220–255° sector; 49% of race time in the 16–20 kt band. No outliers.

Wind angles & sails

Start → SB1 (0930–1210): starboard tack the whole leg, TWA 58–75 — a tight jib reach, AWA ~36–42, AWS climbing 15→20 kt. As the wind backs, course bends 186→172°M and TWA compresses toward ~58–60 — trim progressively tighter from ~1130.

SB1 → finish (1210–1341): a genuine beat, tack angles ±36–44, closing bearing ~260°M against TWD 221–226. AWS 20–22.8 kt: full rail, consider first reef in the gusts near Sorrento 10.

Tides & current

Pt Lonsdale approx: HW ~0200 (1.4 m) · LW ~0830 (0.15 m) · HW ~1510 (1.65 m) · LW ~2120. Four days past full moon (30 Jun) — still a big range. Verify against the official Victorian Tide Tables before dock-out — these are estimated from harmonic patterns.

• Slack at the Heads lags Pt Lonsdale by ~3h: slack ~1130–1200, flood building all afternoon (max ~1500).
• Morning leg south: streams weak north of the Great Sands — negligible.
• The beat is into a young, building east-going flood — adverse from SC19 to the finish, strongest near the channels. Model shows ~0.4 kt but is coarse; expect locally 1 kt+ at the Sorrento Channel piles later in the day. Work out of the stream toward the Sorrento shore where depth allows.
• Slower boats cop max flood + max breeze together — the back of the fleet faces the hardest final 5 nm.

Waves & sea state

• 0.5 m at the start → ~1.0 m mid-bay → 1.5–2.0 m significant at the bottom end, from 206–234°, period stretching 5→10 s (some ocean swell penetrating the Heads).
• Flood under the SW waves flattens the chop slightly, but the beat will be wet and slamming at TWA ~40. Secure below decks before SB1.
• Expect confused short chop over the Great Sands regardless of model values.

Land effects

• Start (RBYC): W-WSW comes off the land — flatter water, puffy and shifty in the first mile. Sight the line bias late.
• Eastern shore run: slight pressure advantage offshore as the gradient builds; inshore lee below Mornington can go soft.
• Sorrento approach: breeze crosses the Nepean dunes — gust/lull cycling and small oscillations inshore, on top of the persistent left trend.

Sky, rain, temperature

~60% low cloud at the start clearing mid-morning, then mid/high cloud filling to 90%+ over the southern bay after 1300. Rain effectively nil; CAPE 30–95 J/kg — no lightning or squall risk. Visibility good.

Air 10.5→12°C. With 20+ kt apparent on the beat it will feel like ~5°C — full winter kit, dry gear for the beat, hot drinks made before SB1.

Sunrise 0737 · Sunset 1713 (= race time limit, DNF after). Optimal finish 1341 leaves 3.5h margin. Moon waning gibbous 83%, not a factor.

Hazards & admin

• South Channel: prohibited under any circumstances (SI C3). The boundary sits close to starboard between SC23 and SC19 on the beat — hard line in the plotter.
• Course: Start → Gate → SB1 (s) → SC23 (pass s) → SC21 (s) → SC19 (s) → Sorrento 12 (pass s) → Sorrento 10 (s) → finish at BYS. Finish between BYS tower post and BYS 0; pass between the red pile east of the Safe-Harbour and BYS 0.
• Shipping: keep clear of all vessels >35 m — the South Channel is Melbourne's main lane, right beside our beat. Engine only perpendicular to a ship's track, return to the same spot, report to RD by SMS.
• Camerons Bight submerged hazards — current NtM 272(T)-26 flags hazards just east of the finish approach. Stay outside the moorings.
• Great Sands shoals + Hovell Pile flank the beat; Anonyma Reef Shoal near the start; keep clear of mussel spat zones.
• Lifejackets: Vic regs mandate wearing in heightened risk — 22 kt gusts and 2 m seas qualify. Call it at SB1 if not before.

Radio & sign-on

• TopYacht sign-on (skipper + POB) by 0830
• RD broadcast 0845–0905, VHF 82
• Warning 0925 · Start 0930 · recalls on 82
• Monitor 16 + 82 throughout · AIS transmitting
• Radio calls: abeam SC19, then 5 min from finish
• Berthing at BYS on Ch 73 · RD phone 0418 396 605

Tactical summary

• Clean start, starboard tack, settle in — a 2.5h drag race where straight-line VMC and trim discipline win. Trim tighter as the wind backs.
• Position for pressure offshore on the run south, but don't sail extra distance — TWA is fixed by the rhumb line.
• Set up for the beat before SB1: rail fed and dressed, jib car/rig for 15–17 kt, reef decision framework agreed.
• On the beat, favour the left (Sorrento shore) for the persistent back and weaker flood; respect the South Channel line and the sands to the right.
• Watch the clock vs the flood — every minute saved before 1400 is worth double against the building current.

Prepared 2 July 2026 from Expedition optimal route (10-model ensemble) + ORCV SIs V2. Re-run the route on Saturday morning's GRIBs before the 0845 RD broadcast.