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Monday, 11 March 2013

Some technical notes on the Atlantic crossing

Some more detailed notes on weather, routing, the boat and our equipment:

Weather

Conditions when we left were quite light, with a big low pressure system sitting over the north Atlantic replacing the Azores high.  The result was quite unsettled winds for a while, with a couple of days of only 10-15 knots.  The sea is the problem, as the waves don’t diminish as quickly as the wind does.  It’s horrible bobbing about with the sails slatting and refusing to fill. For the most part we managed to keep moving reasonably well, and the cruising chute and light genoa helped with this.  After 7 days or so it felt as if the tradewinds had established themselves properly again, and from then on it was much steadier: the wind was generally between force 4 and 5 and from the east or north-east, with 2 metre waves – sometimes more, sometimes less.  The wind strength did vary regularly, meaning lots of sail changes.

Our worst night was after about 6 days.  Thundery clouds built up and we had dramatic forked lightning in all directions around the boat.  In a word, scary.  Most of it was several miles away, but the gap between the flash and the thunder was occasionally short enough to be quite worrying, particularly when the mast makes a perfect target.  We put the handheld GPS and the VHF in the oven in case we got struck (Faraday’s cage..) but this felt pretty futile.  I spent the night watching the bolts hit the water and worrying.  In the morning we had two hours of force 7 or 8 squalls, which we handled fine with very little jib up, but it wasn’t much fun.

Other than this incident, I was surprised how few squalls we saw.  Apparently January is a dryer month than December or November.  There were a few threatening clouds (especially at night, when it’s hard to tell how dark they are), but they often turned out to have little wind under them.  We got some extremely heavy rain a couple of times, and a few showers, but we didn’t see any classic line squalls bearing down on us. 

The seas weren’t very regular much of the time, and were usually on the beam or quarter rather than from behind, and Limbo’s motion could be quite extreme as we rolled our way across them.  If you were parachuted in to ocean conditions it would be very unpleasant, but we’d had plenty of time to get used to routinely much bigger waves than you’d happily sail on in the Solent or the channel.  I’m not talking about underlying long swells, but sometimes quite steep waves with breaking crests.  Limbo has proved to be an excellent sea boat: she bobs over the sea with aplomb, and refuses to hurtle down wave fronts.  Instead she sits back as they pass underneath.  We were happy leaving the forehatch open most of the time.  We occasionally had water on the deck, but never got solid water in the cockpit (although occasionally a hissing wave would creep up and give Limbo a slap, throwing spray over us).

It got gradually warmer as we went, and after a few days we’d finally reached that happy state of keeping watch in shorts and t-shirts.  The temperature was well into the high twenties, and little less at night, but the breeze meant that it wasn’t oppressive.  It was sunny most of the time, with blue skies and classic trade wind cumulus.  We didn’t have any permanent shelter from the sun, but a towel pegged to the sprayhood gave us some very welcome shade in the afternoons.

While it's true that there's not much you can do about the weather once you’re out there, you still really want to know what's going to happen over the next few days: forecasts are very useful to plan sail changes (should you leave all that sail up overnight or not?) and just for reassurance.  As mentioned, we got regular updates from friends ashore and afloat, which was sufficient, but information would also have been available via our SSB receiver. It would have been even better to receive proper GRIB files via satphone.

Food

We stocked up with nearly everything in the Canaries, apart from fresh goods.  In Mindelo we found most of the fruit and vegetables we wanted in the market.  We resorted to the supermarket for oranges, which had been refrigerated, so didn’t keep well and were starting to go mouldy in just a few days (they were very good though, and we managed to only throw out a few).  We washed everything before it came aboard, but there were still maggots in our aubergines...  We kept fruit and vegetables in a hanging net and in a plastic mesh crate, wrapped in brown paper.

We took lots of potatoes, and they kept well, but we hardly used them: rice or pasta is much less hassle at sea.  Cabbage kept excellently, as did onions.  Eggs were fine, turned occasionally to stop them getting stale.

With the exception of corned beef and hot dogs, canned meat (but not fish) was hard to find anywhere outside the UK; you can’t get things like tinned mince or stewing steak.  Even on a boat of Limbo’s size, it would have been good to have stocked up.  Tinned tuna was very useful, as were tinned chick peas, sweetcorn and tomatoes.   UHT yoghurts were easy to find and quite good.  Chorizo was good, keeping well out of the fridge. 

We were well supplied with crispbreads and crackers, but there’s no real substitute for proper bread.  You can get tasteless white loaves which will keep for a couple of weeks, but baking is pretty easy, and we made three or four loaves on passage.  Rising time is minimal in the heat. Natalie also made some banana bread when they inevitably all ripened at once.

Breakfast was usually cornflakes, but we also ate a lot of porridge (we don’t usually – but it was great when you were hungry after a long night watch).

It was hard to find healthy snacks in the Canaries, particularly as they like lots of salt.  We tried not to, but ate lots of crisps and peanuts on watch…

We have a small fridge which was great for cheese, butter, leftover food and - mainly - cold drinks.  A can of something cold and fizzy was a real treat.  It’s too small to keep more than one or two meals' worth of meat or fish in it, so no good for having fresh meat on passage except at the start. 
High-sided plastic bowls were really useful to ensure the contents didn’t end up everywhere.  We didn’t have a rigid menu plan, although we were starting to run out of inspiration towards the end!

Water

We carried around 250 litres of water, as well as a few litres of cans, fruit juice and UHT milk (which seems to taste better than I remember it used to!).  This was spread between two flexible tanks (one under the floor and one fitted in the quarter berth when we were in the Canaries) and jerry cans, which were in the cockpit and the cockpit locker.  I checked our actual tank capacity in the Canaries and found it was quite a bit less than the boat particulars stated – so definitely a worthwhile exercise!   A healthy ration is reckoned to be around 4.5 litres per person per day, but a ‘survivable’ one around 2.5 litres, so we had more than enough for safety.   We could have carried more jerrycans on deck, but I don’t like obstructing the way forward or carrying weight too far above the waterline.   

We rotated between the two tanks, the idea being that if one burst we wouldn’t lose all our supplies, and kept the jerrycans for last as they were the most secure.  We aimed to use the vast majority of our water for drinking. We had an alcohol gel by the sink for handwashing, and washing up was done in sea water, which worked fine.  We had quite regular washes in the cockpit using sea water, but with a fresh water rinse using a garden sprayer, which was effective but used very little water.   I found that shaving could easily be done with half a mug of hot water.  We didn’t go as far as cleaning teeth in saltwater.  We kept a rough check on how much we were using, but had plenty left at the end of the passage (at least 60 litres).

Gas

Our cooker runs off Camping Gaz cylinders.  We had no problems at all getting hold of replacements all the way down through the Cape Verdes (in fact, in Mindelo we got new cylinders at about £5 each!).  A cylinder usually lasts us 24 days, although we used less on the crossing as we weren’t heating water for washing up.  We have a pressure cooker which we used for a few things to save gas (mainly stews and potatoes). Small pressure cookers seem hard to find in the UK - we bought it in Lisbon.

Communications

We opted to go without a Satphone, mainly for cost reasons, but also because we liked the idea of an automatic tracker device rather than manually sending messages each day.  We carry a Yellowbrick YB3 transmitter which, save a few glitches, was great – it kept our position updated automatically on the web for people at home (except for 12 hours when it failed to update..) and let us send and receive short text messages.   The battery lasts for weeks.  A reliable friend ashore sent us daily forecasts (thanks Rob!) and we were able to let friends on Lochmarin know that we’d heard their radio forecast information and position updates on our SSB receiver (a Sony worldband radio).  It was great to know that people were keeping an eye on us and, hopefully, not worrying...

Wildlife

Where were the dolphins?  After being followed by scores of the creatures on our way down through Spain and Portugal, we had only two brief sightings all the way across – pretty disappointing!  

We saw seabirds most of the way across.  Tropic Birds, with their white plumage and forked tails, were particular favourites.  We also saw Storm Petrels and, closer to arrival, the large and pterodactyl-like Frigate Birds.  No whales – not necessarily a bad thing, as some people we know of managed to hit one this year – fortunately without damage!

Power

We use as little power as possible on passage: all our lights, including our tricolour, are LED (with good LED nav lights available, there doesn’t seem much excuse for ‘running dark’ to save power) and we have a very low power AIS receiver - a Vesper Watchmate - which is highly recommended, and incorporates an excellent anchor watch feature.  The AIS displays GPS information so lets us turn our chartplotter off when away from the coast.  

We kept a continuous watch on VHF channel 16 and also kept our echosounder/log running.  We have a small Waeco Coolfreeze fridge, which – while very efficient – was by far the most power hungry piece of equipment.  We think it’s well worthwhile as it let us keep milk, cheese and leftovers safely and have cold drinks.  We have two 30W flexible solar panels (one permanently fixed to the hatch garage, the other movable), which do a lot to help, but we still had to run the engine for about an hour to an hour and a half a day to keep it all running via our two 100Ah batteries. We replaced both of these in the Canaries, finding that the old batteries were refusing to hold much charge after a year or two of use.

Fishing

Well, we tried..we can only conclude that there’s either more skill or more luck involved than people let on, but can’t decide which...  Friends on Amorosa found the packaging from one of their lures was more successful than the contents!  Our tally on this trip to date is one mackerel off Weymouth.   A final tally of 26 flying fish landing on deck at night during the passage (three came straight into the cockpit, which could be alarming) but we never had enough at once to make cooking them worthwhile.  We reflected on how extraordinarily unlucky a flying fish must be to hit a yacht.  We saw them all the way across, and it was great to watch them flitting across the waves.

Entertainment

Natalie got through a few books, but I read far less than I expected.  We have two Kindles (absolutely ideal, although I was fairly reluctant at first) and carried several paperbacks as well.  Our iPod was very well stocked up with Radio 4 podcasts, Desert Island Discs (!) and the News Quiz being particular favourites.  With music, these kept us going through the night watches.   One pair of headphones gave up, but we had three – and a second iPod too – the consequences of being without nightwatch listening being unthinkable! 

Watches

We ran a rotating watch system of three hours on/off from 1800 to 0600, then four hours in the day.  In practice, we stayed up for most of the day after the first few days.  Whoever was coming off watch at lunch or supper time made that meal.  It’s hard to get enough sleep with just two of you, and we felt tired much of the time.    

Gear Problems

Our only gear problem (albeit a potentially very serious one…) was with the rig.  I’m not sure when the damage happened, but about half way across I inspected everything and noticed several broken strands at the deck end of the starboard lower shroud.  Not a good discovery.  However, our spares kit included some bulldog clamps for exactly this eventuality (he wrote smugly), and I used them to fix a wire strop from the chainplate to above the damaged area, which made a strong repair.  Limbo’s rig is 8 years old, so should be well within its expected lifespan, but - ideally – it would have been a good idea to replace it before we left, if just for peace of mind. 
  
Otherwise, there was some wear to the genoa stitching at the foot where it rubbed against the pulpit.  I tried to put some sail repair tape on it (the overpriced stuff seen in most UK chandlers) and it wouldn’t stick... 

Safety

This is a big issue, and is deeply linked to the general seaworthiness and suitability of the boat (a fact which can be overlooked in favour of an emphasis on more bits of gear).  While small, Limbo is a very stable, strongly-built boat with a well-protected cockpit, which meant we felt safe in rough conditions.

We always wore lifejackets/ harnesses when on watch at night; not because we were about to be thrown out of the cockpit, but because the temptation is to hurry on deck to sort out a problem quickly.  If you’re already wearing a harness, you will clip on.  We also have stand-alone (none life-jacket) harnesses which are more comfortable to wear when it’s hot, but didn’t use them.
   
For emergencies, we carry a liferaft and EPIRB satellite beacon, in addition to our Yellowbrick transmitter.  Limbo has two independent bilge pumps, one operable from inside.  The VHF and flares seem unlikely to be helpful in mid-ocean, but you never know. We have a comprehensive first aid kit, which we haven’t used, except for very minor injuries. A knife is accessible in the cockpit at all times for any rope-related incidents.  

Sail Plan

We opted for twin headsails and no main, which worked well.  This has the serious advantage of accidental gybes not being a problem (and we've heard of three boats which gybed accidentally this year - on two this exploded the preventer block, the other was dismasted).  In addition, Limbo isn’t particularly balanced going downwind unless the main is reefed well down – she gets weather helm – and I thought rolling away the genoa would be much easier than reefing the main when the wind got up. 

We had the roller genoa to leeward, poled out with the main boom (this was held independently of the sail, with the mainsheet as an after guy and a three-part tackle vang as a foreguy – attached to a webbing strop around the sailcover then clipped forward to the shroud chainplate). The genoa sheet ran through a block at the end of the boom.  The second sail was hanked on to our removable inner forestay (a proper Seasure lever arrangement installed at expense, but well worth it) and poled out with the spinnaker pole, with a foreguy through a block attached to the forward cleat and an afterguy through another block attached to a stanchion near the cockpit.  This is the system described by Anne Hammick in the excellent ‘Ocean Cruising on a Budget’ and gave a stable and easily-handled set-up.

We mostly had a No.2 sized sail up along with the genoa, but swapped this for a lighter genoa or a cruising chute when the wind dropped below force 4 or so (I never worked out which was more effective), or the storm jib when it was particularly strong.  The No. 2 and the light genoa were cheap purchases from ebay.  When the wind increased we furled the genoa until it was slightly smaller than the No.2, then – if it increased further  -dropped the No.2 and replaced it with the storm jib.  We found that the motion (i.e rolling) was much better if we could keep two headsails up, although if the wind was really strong could simply keep going with a scrap of genoa.  It’s all downwind, so not too much of a problem. 

The wind strength varied between about force 3 and force 6, with a couple of squalls up to around force 8.  We wanted to keep the boat moving well, and changed sails quite frequently.  This involved a bit of scrambling around on the foredeck, which could be interesting.  We mostly played it safe, by taking the harder-to-handle cruising chute or drifter down at night, but there were still a couple of hurried changes in the dark when a particularly black cloud loomed over us!

Seasickness

We both suffer at times, but neither of us was actually sick during the passage.  We took Stugeron on and off, which worked well, and on the whole seasickness wasn’t an issue.  Occasionally we felt queasy, particularly when cooking, but not severely. 

Speed

We weren’t going to press Limbo very hard, but equally on a passage of this distance an extra half knot of average speed, for us, makes a difference of 1 1/2 to 2 days.  We changed sails regularly to keep the boat moving properly, and were pleased to see 24-hour runs of over 130 miles on occasion (with a little help from the equatorial current!).  We averaged 4.6 knots, or 111M per day, which is a good speed for a little boat.

Steering

We steered for a total of about an hour during the 18 days, the rest being taken care of by Wilhelm, our Windpilot Pacific Light.  A good windvane steering system is definitely the way to go on a small (or short-handed) boat, being highly reliable and using no electricity.  It’s probably the most important piece of equipment we carry (as well as being the most expensive!).  With only two on board, the failure of automatic steering on a long passage would be highly inconvenient, to say the least.  An electronic autopilot would be extremely power-hungry – there’s no way we could have kept it going with our set-up – and I’d want at least one independent back-up system if relying on an electronic pilot.

Navigation

Really not very complicated!  The north end of Barbados is 264 degrees true from Mindelo and 2010 miles away.  There’s up to 20 degrees of variation to think about when applying this to a compass course.  The wind was occasionally too far north to make our course under twin headsails (when the apparent wind was more than about 50 degrees off the stern, the windward sail collapsed), but as we went across it became more consistently easterly.  We tried not to worry about a few degrees off either way, although the wind varied enough to make windvane course adjustments quite frequent.  We plotted a Great Circle course on our chart, (the Imray Atlantic planning chart), which is a Gnomic projection or equivalent) and tried to stick to this, but in practice the wind direction had the upper hand.  At this latitude the difference between the Great Circle and Rhumb-line is minimal, and the GPS will give the Great Circle course anyway.

Routing

We’d definitely recommend going via the Cape Verdes.  Apart from being a really interesting place, stopping in Mindelo cut the distance by around 700 miles: getting on for a week on passage for a boat of Limbo’s size.  It also means that you’re straight out into the trade winds, rather than having to hunt south.  We found that it felt all downhill after the half-way mark, and the days passed surprisingly quickly; but still, we were very pleased to get in after 18 days, and an extra week would have made a substantial difference, both psychologically and in terms of carrying enough stores and water.  Heading for Barbados cuts a day off the trip, apart from being a very pleasant island which you won't be able to visit later on (as it's 90 miles to windward!).


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