Transpac Strategy and Tactics Stan Honey May 2019

1. Transpac Strategy and Tactics Stan Honey May 2019

2. Transpac: 5 Races • Race to reach the Synoptic Wind before the glass-off. • Pick and race to your Ridge Waypoint. • Slotcars to the shift • Pick the correct corner on the Run (re tropical waves). Play the shifts, squalls, and cloud streets properly along the way. • Sail in the accelerated wind approaching the Finish

3. Refresher on Convergent/Divergent winds parallel to shore: • In Northern Hemisphere, facing land, if wind blows from right to left, ok to go in. The wind will blow right to the cliffs, and often there will be a stripe of increased wind along the shore. (e.g. Catalina from the West End to Arrow Point. • In Northern Hemisphere, facing land, if the wind blows from left to right, there will be a light zone near shore. (e.g. Catalina on the S side of the W. End, and the Palos Verdes). • Opposite in Southern Hemisphere. • “Bernot on Breeze” by Jean-Yves Bernot, every navigator should own a copy. Terrific reference on terrain effects. Out of print but available. Jean-Yves is the only human who can explain the happy hour back in the trades (veer in S hemisphere). • Friction of land backs the wind. If the back causes the wind over land to converge with the wind over the sea, the wind increases.

7. Catalina tips summary: • Foot across the channel on the lee bow of your sisterships. The first boat to the Island “lifts” in front of the boats on her hip as she approaches the island (current relief). • Don’t get sucked into the Isthmus fan. Don’t approach Catalina E of Howlands, tack before the fan if necessary. • If above the Isthmus fan, ok to play the Island very close, just outside the kelp. Convergent wind. Tack into every point. • Don’t hit the rock (0.85 mi from W End, 0.15 mi off Catalina) • Divergent wind on the S side of Catalina, delay your tack onto starboard at the West End until the wind freshens and looks filled in abeam. If on starboard and it gets light and headed, bail out. • Note that the TWD, at the west end of Catalina, is directly from Hawaii (GC is 245 mag), so delaying the tack onto starboard is not expensive.

8. Reach the Synoptic Wind Day1, summary. • Nothing else matters on the first day. • Know where the Synoptic wind is. • In SW wind tack loosely up Palos Verdes, divergent coast with broad current relief, no need to play really close. • Tack when you can lay the Isthmus, normally get lifted to Arrow Pt., Don’t tack in mid-channel. Foot to be first out of the adverse current. In a fleet the lee bow boat always wins. • Short tack close up Catalina shore, convergent coast. • Don’t tack too soon at the West End and fall into the light air header S of Catalina. • Port tack is cheap insurance. TWD is right from Hawaii at that point. • If Catalina Eddy, sail smart to get to Synoptic Wind. It is absolutely essential to know where it is and get to it. S of Santa Rosa? Between San Nick and San Clemente? • Years with Catalina Eddy can have very windy Westerlies once you get to them.

11. HRRR very good mesoscale model. Free ie legal to get updates during race. To: query@saildocs.com send HRRR:35N,31N,122W,116W|0.2,0.2|0,1..18|WIND (results in 30 kByte file) send HRRR:35N,31N,122W,116W|0.02,0.02|0,1..24|WIND (highest resolution, results in 2 Mbyte file) HRRR updates Hourly Get a big file via LTE before the start. First 8 hours of HRRR is more trustworthy; get hourly HRRR Iridium updates if there is a Catalina Eddy. Fine tune the coverage, resolution, and time extent of the HRRR order to fit your first afternoon/evening needs.

13. Odds and Ends first day tips • Never find bottom-fast kelp in water deeper than 200 feet. • The above is a sensible distance to clear the lee SE of San Nick for both kelp and wind. • Do a complete kelp check the first evening, while there is still good light. • Check again the next morning. • You can smell the synoptic wind when you get to it. It will lift, build, and cool off.

15. Slotcars leg, typically 130-145 W

16. Pick Waypoint on the Ridge • Too far North, and you run out of wind before you get to the shift, have to gybe on horrible angle to avoid getting becalmed; complete toast. • Too far South, you sail extra miles needlessly and boat’s North of you get shift first, gybe out and cross in front of you, mild toast. • Pick ridge waypoint and course based on expected strength and location of High when you are 130-145 long. Use UL charts/gribs, GFS gribs, OPC 96hr prog. • Router will take you too far North. Understand why. • Router is useful to identify N edge of reasonable possible courses. • Perfect ridge waypoint lets you sail slightly hot of inshore vmg angles until the gybes are even. Router can work this out if polars are good at angles somewhat hot of inshore vmg. Study the French. • If your slot ended up too far N, fight S.

17. 500mb charts • Buy Lee Chesneau’s book. • If Omega block, (meridional UL flow) the surface winds behave as if there is a strong surface high even if surface high looks dicey. • If zonal flow, even if the surface maps show a strong surface High, don’t trust it, buy insurance and pick a more Southerly ridge crossing.

18. Race in your slot to the shift • Best ridge crossing will give you confidence to sail ocean-downwind angles. I.e. sail fast and hot to the lift. • If you’re too far N, you will sail inshore-downwind angles and will be willing to gybe aggressively to sail on slightly unfavored port poles. Decide how much to pay… 10 deg? • Even if you’re on perfect slot, still gybe on big shifts in squalls. • Expensive to change lanes to left, but more expensive to not do it if necessary. E.g. 1999

19. Sources of Weather Data

20. Communications tradeoffs and observations • After prep only use free public data. It is legal to pay for communications but not data. • Iridium • $70 per MB, unless you have a Go! Unlimited plan, which may have minimum duration. • 2.4 kbps • 30kB gribs a reasonable max. • I use SailMail, set up a subscription for gribs, dedicated “route”, SailMail doesn’t send superseded gribs. I do this even as a backup on a maxi. • Multiple moving satellites see around carbon sails. • Substantial improvements from new constellation of satellites. (robust connections, stronger signals) • Inmarsat • $15 per MB • 150 kbps • 11 inch diameter dome • Only one satellite per region that can be locked by carbon sails. Need Iridium backup. • KVH V3 HTS • $1 per MB • 1000 kbps • 14.5 inch diameter dome, hardware more expensive. • Multiple satellites can see around carbon sails • Glasswire • Free easy firewall usable to block undesirable internet users. SailMail/AirMail solves this for Iridium.

21. Watch for Cutoffs • Know your Lows • Extratropicals, Subtropicals (cutoffs), Tropicals • Be on the lookout for a cutoff (subtropical) low S of the Pacific High. • Go N of it if you can, or far S. Avoid going just S of a cutoff. • Important to understand subtropicals anyway for seamanship • Halloween Storm 91 (perfect storm) • Fastnet 79 • Hobart 98 • Bad if comma shaped, top blown off by jetstream, big temp gradient on side closest to the pole, or new (tight) core. • Transpac cutoffs are not dangerous other than to your results.

24. Rules of Thumb • NEVER trust rules of thumb. • 7-8 mb from center of high at your closest point along 130-145 deg W. • If building High with Meridional UL flow, 6mb can be ok. • If fading High, Extratropical Low passing N of High, Zonal flow, High oriented E-W, then more than 8mb at the closest point. • Generally 27-30N at 130. 30 with great Highs, 27 with dicey Highs, 26 is extreme and VERY expensive but has been necessary occasionally. • Much better to figure it out than to use rules of thumb. • Old-timers sailed through “Point Reliable” (26n 137w) and “Point Most” (25n 147w), in heavy boats with lousy forecasts. Even then it was easy to beat that approach with hand-routing on Fleet Code (connect-the-dots, weathermaps).

25. What if the High goes bad? The high goes bad by turning into an E-W ridge and sagging to the S, often triggered by a large extratropical moving W to E, N of the High. Decide whether you can get to and stay in the Trades that will live South of the ridge, if so torture the boat deep, and gybe on somewhat unfavored ports to get S. If you can’t keep up with the Trades moving S, consider whether Trades will fill from the NW? They rarely re-fill from the S. Sometimes it makes sense to stay above old ridge, beating in light Westerlies (but still moving), to be the first to get the new trades associated with a new High filling in from the NW. Think ahead about how the trades will fill in. Trust the GFS given no alternatives.

28. Tradewind Run • Nighttime dipole squalls • Daytime cloud “streets” • Daily wind shifts; late afternoon lefty. • Get back to the necessary pole to get to the chosen corner. • Some races 50 gybes are necessary.

29. Squalls • Dipole squalls can self-propagate and last for hours. Need to gybe off of headers to stay with them. Works great for fast boats. Wind toes-in in front. • Monopole squalls, “popup” squalls, generally only one pass, wind toes-out like a catspaw in front. Short-lived due to suicide by cool-pool. • Avoid area behind squalls. Port gybe exit is much safer. Squalls “sail” on starboard gybe. • Go to school on the early squalls in a given night. Mostly righty. • Avoid squalls after dawn. • Once again, avoid squalls after dawn, very important. • Don’t confuse the convergence zone as a lefty squall. It is a long line of cloudy left shift. Sometimes have to change to a headsail to get through quickly. Sometimes you’re delighted to get the free southing.

30. Prevailing wind Gust front Light zone behind Daytime “popup” squall. drawing by Mike Dvorak Popup squalls commit suicide by creating a “cool pool” below themselves.

31. Prevailing wind

33. Overview Dipole Squall Tactics • Squalls move about 15 degrees to the right of the surface wind, and about as fast as the surface wind that is unaffected by the squall. About like a turbo sled. • Conventional sleds and TP52’s are about the right speed to gybe in front of a dipole squall, gybing off the headers. • Slower boats, gybe to port for the overall right shift, sail deep on port through the squall, stay on port until clear of the light air behind. • Faster boats (maxis) avoid the squalls, gybe around them and overtake them.

35. Cloud Streets Tactics Summary • Watch out airplane window on your return. Streets are more common that we think. • On starboard gybe, you stay in constant position relative to the streets. • On port gybe, you move across lanes much quicker than it would seem. • More wind on the edges of the clouds. 1 knot.

36. Final Shift • Right corner generally pays because of continuing veer. • Left corner pays if you are leading a tropical “inverted trough” to the finish. • Right pays big if you are following a tropical trough to the finish. • So keep your eye on the tropical “inverted-troughs”. • Don’t overstand, but aiming for Kalaupapa provides some cheap error margin. • Mind the “happy hour lefty” each evening.

37. Note that even weak tropical remnants have windy backs in front of them and light veers behind them.

39. Finish • Gybe for Kalaupapa. Coming in E of Kalaupapa is dicey unless you have lots of Kenwood experience. • Sail in accelerated wind N of Molokai and W of Ilio. Molokai ducting overcomes divergence (cliffs). • Straight in, from Ilio to ¾ mile off of Koko works for slow boats (with deep vmg angles) in windy (i.e. NE wind) years. A no-gybe straight-in approach can be welcome on these boats. • Have to gybe just past Ilio on lighter (i.e. E wind) years especially on fast boats that have hotter vmg angles. • If really windy, a gybe at Ilio can be hairy due to confused seastate. If too dicey delay to mid channel where waves are longer and uniform. • Avoid area near Makapu. • Close to Koko Head is fine (convergent wind). • Heading strong puffs after Koko Head in windy (NE wind) years. Watch for them. • In light (E wind) years, have to do a few gybes along Oahu, stay out of the bays. • Navigate to the buoy.