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Navigator Playbook — Lupo Di Mare

Navigator/Tactician role. Covers what is unique to this role; watch system, squall protocol, and safety basics are in Crew Orientation.

TL;DR

  • Lupo's default is T-CL — minimize maneuvers, hold the briefed lane, pre-commit at gates.
  • S3 polar (10% degradation) for every routing scenario. Never present S0/S1.
  • Stream entry sail commit at T-2 h / 50-nm pre-gradient window. A peel inside the Stream is skipper-cleared, not a default.
  • Two-source rule: SST + altimetry must confirm before any T-CF / T-CCR / T-ME commit. RTOFS-only ≠ actionable.
  • T-CL gate on every deviation: data trigger named · maneuver count counted · skipper concurs.
  • Wake thresholds: see table below. Don't sleep through them; don't escalate without them.

Wake Thresholds — Off-Watch Interrupt Contract

Trigger Threshold Source
Wind divergence from forecast ≥10% / ≥30 min card_01
Wind shift, offshore ≥20° / ≥1 h card_02
Current divergence, in Stream >1.5 kts vs forecast card_04, card_05
Current divergence, offshore >1 kt persistent / >30 min card_07, card_10
Wind <5 kts, mid-ocean sustained >3 h, fleet catching card_07
Wind <5 kts, Bermuda approach >60 min card_08
Squall echo, in or near Stream inside 30 nm → navigator; inside 10 nm → all watch card_09, card_05
Any tactical deviation from pre-race plan T-CL gate must clear (see below) walkthrough — Gates 1–3

Wake Skipper for: squall threat inside 20 nm; any T-CL deviation proposal; rig/sail damage limiting routing options; current >2 kts adverse with detour gain >2 h (card_10); WCE routing change at Stream exit (card_06); structural concern (card_10).

Triggers below these thresholds defer to the next watch handoff brief.

T-CL Gate — Clearance for Any Route Deviation

Every deviation from the pre-race route must clear three gates before execution:

  • [ ] Data trigger named — name the specific observation (SST, RTOFS, GPS/log, instrument, model). "Looks good" is not a trigger.
  • [ ] Maneuver count counted — Lupo is T-CL. Name required maneuvers; confirm crew can execute in current conditions.
  • [ ] Skipper concurs — verbal concurrence. If Skipper is sleeping, the deviation is not urgent enough — hold or wake per the table above.

If any gate fails: default to T-RH (rhumb) or hold pre-race plan. Brief Skipper at next handoff on the considered deviation.

Tactic Commit Checklists — Go/No-Go Before Routing Changes

Before committing routing to a current feature:

  • [ ] SST imagery confirms feature exists and is positioned as forecast
  • [ ] Altimetry / SSH anomaly confirms feature (independent of RTOFS)
  • [ ] Routing software at S3 shows ≥8 h savings vs rhumb
  • [ ] Feature is within 30–50 nm of rhumb crossing latitude

All four must check. Any failure → treat as H-HR; fall back to T-RH or T-PF.

Highest-reward / highest-risk tactic. Before commit:

  • [ ] CCR confirmed by SST (cold core, 5–14°F cooler than surrounding)
  • [ ] CCR confirmed by altimetry (SSH anomaly shows LOW / negative SLA)
  • [ ] Western limb within 40 nm of rhumb line
  • [ ] Routing software at S3 shows >6 h saving vs rhumb after maneuver cost
  • [ ] Forecast wind supports routing angles required

Any failure → default to T-RH or T-PF. T-CCR is incompatible with T-CL — committing means accepting multiple peels.

Connected feature (not isolated). Before commit:

  • [ ] SST imagery shows Stream axis bent significantly south of climatology
  • [ ] RTOFS shows NE flow ≥2 kts in meander's eastern limb
  • [ ] SSH anomaly does NOT show isolated LOW (confirms connected, not CCR)
  • [ ] Exit latitude pre-calculated at T-1 brief
  • [ ] Crew briefed on exit plan

Exit is harder than entry — favorable current tempts overstay. Card 06 — Decision Threshold (Meander exit check): 15° bearing change from pre-planned heading → exit now.

H-HR = high-risk/high-reward label per Routing Hypothesis Labels.

Watch-On Duties

Navigator runs a continuous loop, not a watch shift. Briefed cadences (GRIB ingest, calibration, satellite-comms) are in Race-week deliverables below.

  • Ingest next GRIB and RTOFS/HYCOM on briefed schedule — do NOT wait for "when interesting."
  • Maintain rolling 6-hour and 24-hour wind, pressure, and current picture in Expedition.
  • Run routing scenarios at S3 (10% polar degradation) for all tactical decisions. Never present on S0 or S1.
  • Cross-check current: GPS speed minus log = experienced current. Compare to RTOFS/HYCOM at same lat/long.
  • Cross-check wind: instrument TWS/TWD vs forecast; flag divergence per wake table above.
  • Brief on-watch Watch Captain at every watch start: route, next decision point, current data trend, forecast changes.
  • Maintain T-CL gate discipline on every deviation.
  • Confirm instrument calibration on briefed cadence.

Watch-Off Duties

  • Sleep — a fatigued navigator makes worse routing decisions than a well-rested one.
  • Before sleeping, brief Skipper on next forecast inflection point so in-watch decisions don't require a wake.
  • Interruptible per wake thresholds above.

Routing tool touchpoints
  • Expedition — primary routing engine. Run at S3. Pre-compute Stream entry options (early/planned/late) before T-1. Pre-compute meander exit latitudes if T-ME in play.
  • Polars — 02_polars/lupo_polar_analysis.md. The ORR cert polar is FINAL and is the routing source-of-truth (Cert #US43225, GPH 557.1; built into nav/polars/lupo.pol) — load it in Expedition and run at S3. Lock the Expedition routing file before the start and do no live re-runs once racing (RRS 41). (Confirm the exact lock time at the T-7 brief.)
  • GRIB — GFS, ECMWF, and HRRR for nearshore. Compare two-model agreement before committing forecast-driven decisions.
  • RTOFS / HYCOM — Stream current forecast. Use both; if they disagree, mark feature as H-HR.
  • SST imagery — independent current confirmation. RTOFS-only is not actionable. SST + altimetry required for T-CCR or T-ME commit.
  • Altimetry / SSH anomaly — second independent confirmation of CCR/meander features.
  • Radar — squall detection at 30/20/10 nm (see crew_orientation.md — Squall Protocol).
  • AIS — fleet context only. Do NOT rely on AIS-only competitor data for tactical calls.

Sail Change Choreography

Navigator triggers sail changes; does not execute them.

Pre-Gulf Stream sail commit: - At T-2 h before SST gradient / 50-nm pre-gradient window: commit to Stream entry sail. - Communicate to Watch Captain; WC briefs Bow, Pit, Trim, Driver. - Chosen sail is up before crossing the gradient. A peel inside the Stream is the skipper's call, not a watch default. (Card 04)

General sail change call: - Navigator advises Watch Captain on sail change based on forecast wind trend. - Watch Captain decides execute / defer / hold. Navigator does NOT make sail-change calls directly. - Any peel in a high-stress phase (Stream, squall, night): navigator must clear with Skipper.

Reef call: - Navigator advises based on forecast TWS trend and crew fatigue. - Watch Captain decides; reef goes in proactively, not reactively.

Comms Protocol

Navigator calls in: - "Next decision point in [N] hours: [decision]." — to Watch Captain at every handoff. - "Forecast change: [what changed, action]." — when new GRIB/RTOFS changes the picture. - "T-CL gate: [data trigger / maneuver count / skipper concurs]." — proposing a deviation. - "Squall threat: [distance, bearing]." — any convective cells inside 30 nm.

Navigator calls out: - To Watch Captain: continuous routing context and next-decision-point brief. - To Skipper: any T-CL deviation proposal; squall threat inside 20 nm; rig/sail limiting routing. - To Trim/Driver: target TWA and target BSP per current polar mode. - To Bow/Pit: which sail is next — at least 30 min notice for non-emergency changes.

Failure Modes

# Mode Symptom Recovery Prevention
1 Acting on RTOFS-only data Routing to a forecast feature smaller/weaker/displaced; distance added Revert to T-RH or T-PF; debrief SST + altimetry is a hard gate. No confirmation = H-HR, do not commit.
2 Routing at S0/S1 polar 5-hour saving forecast doesn't materialize Re-run at S3; re-brief S3 is the default — lower degradation is benchmark-only
3 Late Stream entry sail commit Bow on foredeck in steep chop attempting peel Abort peel; hold sail until exit; debrief Commit at T-2 h / 50-nm window, no exceptions
4 ORR polar arrives late (post-T-3) Routes still on interim chart; pressure to re-optimize after the start Freeze the interim chart at T-3; lock the Expedition file before start; brief crew on the locked plan T-4 receipt target; never re-run live (RRS 41)

Race-Week Deliverables

Item Owner Target
GRIB update frequency offshore Skipper T-7 brief
Wind-divergence wake threshold (beyond ≥10%/≥30 min default) Skipper T-7 brief
Instrument calibration cadence Skipper T-3
Expedition .trip file management (master, sync) Skipper T-7
ORR cert polar receipt + Expedition reload + route re-run Navigator T-4 (Jun 15); freeze interim at T-3; lock file before start
GRIB satellite path offshore (SSB / Iridium) Skipper T-7
sail-iq integration vs nav/PRE_RACE_CHECKLIST.md Skipper T-7

Do not invent values pre-confirmation.

Cross-references

Onboard cards: - Card 03 — Pre-Gulf Stream - Card 04 — Gulf Stream Entry - Card 06 — Gulf Stream Exit - Card 07 — Mid-Ocean Transition - Card 10 — Tactical Scenarios

Tactic catalog: - T-CL — Conservative Lane - T-CF — Current First - T-CCR — Cold Core Ring Exploit - T-ME — Stream Meander Exploit - T-WCE — Warm Core Eddy Avoidance

Reference: - weather_analog_framework.md - Daily Analysis (automated brief) - crossing_strategy_catalog.md - winner_route_summary.md - 02_polars/lupo_polar_analysis.md — ORR cert polar (final)