Monday, 2 November 2015

Reunion to Richards Bay Passage Summary

Hi everyone,
Here is a summary of our passage.  This passage is widely considered challenging due to the passage south of Madagascar and the difficulty (impossibility with today's technology) of predicting destination weather prior to departure.  The weather on the South African coast is notorious for its hazards, particularly due to the Agulhas Current.

Zen Again in Tuzi Gazi Marina

First the usual track and speed plots.  The images are small due to the satellite link we're using to post at present.

Zen Track

Now the vital statistics…
  • Distances/Speeds
    • Route Distance = 1400nm
    • Logged Distance = 1534nm
    • GPS Distance = 1524nm
    • Duration = 11 days 2 hours
    • Average speed = 5.8kt
    • Average day's run = 138nm
    • Best day's run = 153nm (6.4kt)
    • Minimum boat speed = 3 kt
    • Maximum boat speed = 10.5kt (surf's up!)
  • Weather
    • Minimum wind speed = 0 kt
    • Maximum wind speed = ~35kt
    • Apparent wind angle range = 50 to 150 (we don't "do" running, choosing to broad reach instead)
    • Seas up to 4m
    • Swell up to 3m
    • Wide variety of weather, including an 8 hour electrical storm
  • Engine
    • Total = 72 hours
    • Driving = 68 hours
    • Charging = 4 hours
  • Consumption
    • Water = 120 litres
    • Fuel = 144 litres
    • Books = 10 (5 + 5)
  • Failures (all to be confirmed and all from near-miss lightning strike)
    • Primary autopilot controller
    • SeaTalk/NMEA interface box
  • Stars
    • The boat!
    • Backup autopilot
    • Craftsman CM3.27 engine
    • Satphone.Me email system (over Iridium GO!)
    • PredictWind Offshore app (over Iridium GO!) for obtaining GRIBs
    • qtVlm GRIB viewer and weather-routing software
    • SeaIQ iPad navigation software
    • Icom HF/SSB radio

The passage down the E coast of Madagascar was quite pleasant with light to moderate winds.  We encountered a strong negative current on the second night out.  The next morning we gybed and headed W to find positive current.  This worked well and we then managed to stay in positive current around the S of Madagascar.

The rounding of Madagascar is one of the critical phases of the passage.  One of the boats ahead of us rounded 150nm S of the island and experienced atrocious conditions.  Their SOG got down to zero with 5 knots of boat speed.  They were pooped and their cabin was flooded to floor-board level by the wave.  Based on that experience boats following them rounded the island about 80nm off, where there was a W flowing current.  We rounded 70nm off and experienced areas of 4m breaking waves which the boat handled well.  I would NOT have wanted to be beam reaching in those areas!

Running W past Madagascar

The passage onward to South Africa centred on trying to stay in positive current.  Our gybes were all timed to do exactly that.  Throushout the passage we used RTOFS current GRIBs from SailDocs and OSCAR current GRIBs from sv Sarana.  Although the data wasn't perfect it was extremely helpful.  We also tried to avoid areas of rain shown on GRIBs.  The one area we went through gave us an 8 hour electrical storm in which we suffered a near-miss lightning strike.  We only skirted the periphery of this system so I would not have liked to see its heart.

The last three days were spent in light winds, with a strong southerly buster forecast for the South Africa east coast after the light period.  We motor-sailed for 2.5 days to get to Richards Bay ahead of the buster.  When we arrived a strong NE wind was building up.  NE winds generally precede S busters.  The buster arrived in the early hours of this morning.  More on that in another post.

Sunrise 50nm E of Richards Bay

Overall the passage was a great experience.  Arriving in another continent is special.  We're looking forward to doing the safari thing. There are boats here from many countries including UK, Ireland, US, Sweden, Finland, France and no-doubt others.

We still have 900nm to go to Cape Town to complete our "mission" this year.  So far this year we've logged just over 6000nm.

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