The Southern Indian Ocean is notorious for strong winds and big swell and I must admit….being in SE Asia for almost 6 months made me soft! You would think on an 1100 mile passage that could last just over 7 days is really “nothing” compared to crossing the Pacific Ocean which was over 2,600 miles and took us 23 days, but they are very different oceans with very different challenges….for us, we HAD to have a good (enough) weather window to make this passage south!
Challenges? Let’s see….Wind, swell, south equatorial current, and possibly not enough diesel if we had to motor into big swell (remember we motored all the way to Chagos)….
The Challenges: A Quick Lesson….
Can you notice how the wind direction spirals in 2 opposing directions between the high and low pressure systems? Additionally, can you see the “lines” getting “squished”?….the closer the “lines”…the stronger the winds. Near Chagos, there is a large area of “blue” which generally means light winds but lots of squalls…this is where (I believe) the ITCZ is sitting.
Above is a classic example of the low and high pressure systems (moving west to east) that are happening during this cruising season. As you can see, one high pressure system (wind direction is counter clockwise) is being followed by a low pressure (clockwise) being followed by yet another high pressure system. You can image what comes next….you guessed it, another low pressure system. Additionally, near the equator (Chagos…. really) you have unstable weather, or what “they” call the Inter tropical Convergence Zone. The ITCZ is basically where the north/south trade winds meet near the equator, mostly. It brings clouds, thus rain, and generally lighter winds. The ITCZ is responsible for dictating “wet/dry” season in tropical regions. It is not static and it moves and between the months of May-June is the transitional period when it starts to move North.
When two systems (1 low and 1 high) push against each other, it creates the stronger winds…up north theses strong winds are not really able to dissipate due to the ITCZ so the wind stay “strong” the closer you are to the high/low systems…basically the farther south you travel , the stronger the winds will be….and so will the swell…at least that is how I understand it!
We also had to think about how strong the South Equatorial current could be….as it flows east to west…we didn’t want it to push us too far west otherwise we could sail right by Rodriguez?! We had no idea how strong it would be or how far south it would effect us so we need to regulate how we hold our course to determine how our point of sail would change thus, the comfortably of our passage.
Another challenge is that we can’t just go in any direction we wanted to leaving Chagos….we HAVE to go around the large Chagos Archipelago. The 2 options (East or West) would be entirely dependent on the weather conditions when we choose to leave Chagos.
- East route – Need very light winds and swell to head SE and south past Diego Garcia …. approximately 150+ miles before we can even start to think about baring west at ALL (+/- 24 hour period). Because in the beginning we head east, we have a slightly larger margin to bare west for our duration of the passage, but not too much, only when conditions call for it, possibly making it more comfortable and really we still want to head as far south as possible. BUT….there is no protection from any land therefore we would receive the full force of swell and that would be the major concern for speed and for comfort right from the beginning of the passage.
- West route – Because we have the protection of the land (really I mean reefs), the swell could dissipate and the wind could give you a good point of sail. This would give us a bit of reprieve to the heavier conditions farther south. BUT….. because we headed west in the beginning, we will have to commit to a southern course for a much longer duration without bearing west to accommodate weather conditions which could mean an uncomfortable point of sail in the middle and end of our passage.
The Strategy: In general …..
In short…think on a spectrum of:
- Heading “West = comfortable” and “East = uncomfortable”
- The farther “North = weaker winds/swell” and “South = stronger winds/swell”
For this passage, taking the rumb line is just not possible…well it could be after you dodge the archipelago, but from our research, nobody does and it is advised to approach Rodriguez from as far E as possible. To keep us safe and comfortable as possible, we want the swell, as close to the beam (hitting us about the middle of the boat) as we could….. the taller the swell, the more important it was to keep the swell to our beam. If the swell hits us on the nose (the bow) it will be similar to hitting a wall of water….slowing our boat speed and would most definitely make for a wet ride as we pound down into the waves and create water to splash over our dodger and possibly into our cockpit. If we keep the swell close to the beam, it is more likely we could “move through” them, though the ride could be more rolly….but better than smashing down into them.
The wind strength was a lesser concern, besides the fact stronger winds bring larger swell….but we knew we would see 20-30 knots of wind down south here. Nonetheless, you don’t want to go directly into the wind either so keeping the wind direction as close to our beam was also most desirable.
…So to achieve this, assuming the farther south you go the stronger the winds and the taller the swell would be, we want to head due south as long as possible until it becomes too uncomfortable. Generally speaking, the winds and swell farther north are weaker therefore early on the passage we want to take advantage of this and head as far south (or even east?!) to compensate for a possible change in course later due to the swell/wind directions.
The choices: The ever changing minds…..
We must of changed our minds 10 different times whether to head east vs. west in a duration of about 2 days….
The goal was to go to Rodriguez but by chance the weather would not permit us, or we deemed it either unsafe/too uncomfortable…we would either head to Mauritius or in a really tight pinch…head to the Seychelles. Going to the Seychelles or even Mauritius, taking a western exit was an easy choose. However, heading for Rodriguez, the choice to head east vs. west was harder as we had no idea of the ACTUAL conditions we were going to be faced with. Past cruisers had reported winds in this area seem to understate by about 5 knots and wind direction slightly off to the SE by a few degrees compared to the predictions on different weather models ….I honestly don’t know how meteorologist do it…. though I guess these days weather predictions are all generated by computer algorithms?!
The Plan: At least for now….
The current weather window we choose was actually pretty good. If I would of had the foresight to take screen shots of Predict Wind to show you what we were seeing…it would of been a better dialog. But I didn’t….
In our log book I had written down the following: “W passage – lighter winds (10 knots) and can motor though waves (1.5 meters). Better 1-2 days until the wind fills (15 knots gusts up to 20 knots) about mid passage. Keep heading south until it gets too uncomfortable. Last 2-3 days we expect 25+ knots possibly 3-4 meter swells at 9-11 seconds. ETA – Thursday afternoon or Friday morning. Average speed = 5.5 knots SOG”.
The Passage…..
Our track is the purple and blue line and it looks very close to our desired route above. The triangular marks are the way points of SV Neptne’s Highway that left 1 1/2 days earlier. You can see that weather conditions allowed them to take more of a rumb line than we did.
Day 1 Log Book: AM: Left anchorage 9 am with sunny skies. COG until turn: 247, engine on for 9 hours at 9000 RPMs. Low swell, Winds: 5-10 knots. Apparent wind angle: 70-110 port, Avg. SOG: 6.22
PM: Squalls, makes for head winds and winds from behind for about an hour after passing though a squall. Turn for COG: 202. Wind: 8-14 knots, Apparent wind angle: 50-60 port, Avg. SOG: 6.3
Our view for the first day out….blue skies and puffy white clouds….it seemed to be a good sign : )
Day 2 Log Book : AM: Sunny skies, sailing at COG: 195, Wind: 10-15, Apparent wind angle: 50-60 port, Avg. SOG: 6.2, Swell: 1.5m SE.
PM: Wind dies/shifts to 8-10 knots, Apparent wind angle: 40-80 port, COG: 188-197.engine on to keep a SOG of +6 knots, engine temperature gauge is running hot. Engine off early am of the 24th.
This is pretty much how we “rolled” for day 1-4 until we started to reef the main on day 5.
Day 3 Log Book: AM: Wind increases: 8-14 knots, Apparent wind angle: 60-80 port, COG: 195-200, All sails up, Ave SOG: 5.6, noon-almost no clouds in the sky, engine back on 3 pm.
PM: 6 pm engine off and changed route on chart plotter, results in off course about 19 miles. Changed COG: 220 to get “back on course”. Wind: 8-14 knots, Apparent wind angle: 75-110 port, Swell: 1.7m SE. Avg. SOG: 6.2. Early morning-engine on as wind die to 5-9 knots.
NOTE: As we checked weather, it was becoming clear to us the last few days of our passage was going to be really rough with winds and swell coming from the SOUTH….that is not a scenario we wanted. So with the swell so manageable we wanted to get as far south as we could. We could of sailed but we feared it would not be fast enough over all to get us south enough before everything went to “shits”… (LOL)
Underway, we sleep on the couch (see the pillow behind Trevor) but we like to have the fan on just above us to keep us cool. The toggle switch went out right before Trevor headed to bed…so he decided to fix it right then.
It’s still bloody hot!!!! Trevor is a “sweat monster” : )
Day 4 Log Book : AM: Now only 8 miles “off course”, Wind: 8-12 knots, Apparent wind angle: 60-90 port, Swell: 1.5m SE, Avg. SOG: 6.6
PM: 6 pm engine off, changed bearing COG: 210, Wind: 9-15 knots, Apparent wind angle: 40-80 port, Swell: 1.5m SE. Midnight – 15-20 knots, Apparent wind angle: 60-70 port, COG: 200. Now sluffing left of course. Avg. SOG: 6.5
NOTE: After we changed course on our chart plotter and were “off course” 19 miles, we thought we should get back to our “course line” by heading west and changed our bearing to 220 degrees…NOT A GOOD IDEA! We should of just kept our original bearing of about 195 and kept heading south. Nothing major happened but it added to our already stressed out “first mate” (that’s me) when we started to get TOO close to our course line, afraid we were too far west.
Little guy…surprisingly it was the only flying fish we had on deck…. 
Started to sees cargo ships….Can’t see the rest of the cargo ship because the rolling swell is in the way : )
Day 5 Log Book : AM: Sailing with reefed main, mizzen down, noon, reefed Jib. Wind: 15-20 knots, Apparent wind angle: 90-100 port, COG: 210, Swell: 1.7m SE, Avg SOG: 6.7
PM: Midnight, wind dropped to 12 knots, Apparent wind angle: 80-90 port, COG: 207, Swell 2m SE. Current/waves pushing us closer to course line. Now only 2 miles left “off course”.
Day 6 Log Book : AM: Noon made turn and engines on, COG: 230, Winds dies to 5-9 knots, Apparent wind angle: 140-160 port, Swell: 1.5m SE, Avg SOG: 6.3
PM: 6 pm wall of clouds on horizon. 2nd reef in main and 3rd reef in jib in anticipation of what was to come. Engine still on, Wind: 10 knots, Apparent wind angle: 80 port, COG: 245. Midnight cloudy but no rain, Wind: 12, Apparent wind angle: 90 port, COG: 250. 3:30 am engine still on, Wind: 15-20, Apparent wind angle: 30-60 port, Avg. SOG: 5.6, Swell: 2.5-2.7m. Sea water over dodger. Slept in cockpit.
This was the squall line we were headed into so we started to prepare for the rough and wet ride…..the wind had dies down to almost nothing…literally the clam before the storm…hours before we had about 2 meter swell…now the sea looks like a bathtub?! 
….Trevor out on deck putting our second reef in the main sail, and a sliver of jib out.
Put up our vinyl enclosure…. 
…..”hummmm?!”…. 
….so glad we had the enclosure made back in New Zealand, it kept us dry…mostly!
Day 7 Log Book : AM: 9 am, engine off, Wind: 20-25, Apparent wind angle: 90-100 port, COG: 250, Swell: 2.5m SE, Avg. SOG: 6.25; Noon crazy swell, rainy, stb rails in the water.
PM: 6 pm COG: 270, Wind 30 knots, gust to 40, Apparent wind angle: 110-120. Reefing Jib = BLOW OUT! Engine started. Swell: ??? it was dark but could feel big waves hitting the boat about 90-120 degrees. Sleeping in cockpit. On the 29th 11 am, made port.
We believe the below photos show swell of about 3.5 meter ….. no video…it was way too rough. The noise we heard from both the waves and the creaking of the boat were making me really nervous….so Trevor played really loud music for us in the cockpit to keep our minds busy…I had no idea Trevor knew all the words to Taylor Swifts songs?!
About 7 pm we were in it…we were seeing gusts of 40 knots. So we decided to reef in the jib a little more and …BAM!!!!…. we heard it blow! Trevor saw a “black dark space where the sail should of been” first as we had a light on the fore-deck on and we rolled it in within minutes. I guess it will be the double reefed main sail the rest of the way. It was dark so we have no idea how big the swell was…I was actually thankful NOT to see the waves!
I took this photo minutes after we blew out our jib…. 
Of course we couldn’t capture the moment but after we got to port and the wind finally backed down, we were able to roll out the jib to see the damage…we are pretty sure this can’t be repaired. Really, we had been talking about replacing it for months and just never pulled the trigger so it is really our own fault.
Land HO!!!
This is what 30-40 knots of wind will do to a flag….. 
This was so funny, or maybe you just needed to be there…..after not sleeping very much for the last few nights I guess we were just in a strange “zone”….Trevor looked up at one point and said, “Shit, there’s land!”. We hadn’t seen it over the swell until we were pretty close…. it was time to start getting excited to stop moving and head to port.
Flo at the concrete wharf at Port Mathurin, Rodriguez. Thankfully Harry was there from the Coast Guard to catch our lines as the large black rolling bumpers was going to be difficult for me to jump onto being tired as I was. And thankfully, being in the lee of the island meant we had protection from wind and waves and we were grateful the “ride” was over.
Honestly it wasn’t the worst passage we have been through… that would have to be our passage from Fiji to New Zealand. Learning from our passage from Fiji to New Zealand, we had prepared ourselves and the boat for safety. However, we must admit, the Indian Ocean is a different beast: The winds, for sure, are consistently stronger than we have experienced….but we felt comfortable with “Flo” and how she handles in strong winds, because we have been there : ) Our major concerns was the large swell that accompanies the stronger winds! We have not seen 4 meter swells before…maybe 3 meters on our passage from Fiji to New Zealand, but never 4 meters. The seas here seemed to be more erratic and confused…periods between waves seem shorter which means the ride was less comfortable…it just seemed so unlike other ocean passages…or maybe we forgot how it really was?!
We don’t know how or why this ocean seemed different….maybe it has to do with the land masses that surround this ocean (compared to the vastness of the Pacific Ocean) and how that contributes to the strength of winds, or whether it’s the way the high/low pressure systems seem to be so close together that there is no time for the winds or swell to dissipate….whatever it is…it’s no joke!
We are glad we made the decision to come south to Rodriguez when we did, even though we missed out on enjoying the “untouched” beauty of Chagos for 2 more weeks. Not many decide to go this route while others want to come here but weather dictates otherwise. In fact, when we were in Chagos, 3 other boats had plans to come south but had to change their plans and head for the Seychelles due to weather conditions. They even extended their mooring permit in Chagos (not an easy task we hear) to wait for a proper window to come south…it just never happened….. we left at the right time, even though it was rough the last few days. It seems to be true, the later in the season, the winds fill in and it’s harder to head south.
We are the 5th boat to make this port this cruising season and it’s time to rest up : )
Love the Mauritius flag…however we learned there is a separate Rodriguez flag…..will need to get one of those : )
Up Next: Rodriguez: “Once…. Twice…. Three times we anchored!”