It's a Big Ocean
Caramor - sailing around the world
Franco Ferrero / Kath Mcnulty
Wed 11 Mar 2015 11:46
Enough 'chick lit', now for some technical stuff.
Wednesday March 11, 0900hrs, end of day 3, start of day 4.
A big decision for any boat heading for Brazil is where to cross the ITCZ (Inter Tropical Convergence Zone), better known as the Doldrums. This is a band of low pressure and light winds or no winds interspersed with fierce squalls. It starts a few degrees north of the equator and goes down to just below it. The band is wider on the African side and narrower on the American side. However, if you cross too far over towards America you risk being swept towards the Caribbean by the Guiana Current and having the SE trades that form south of the equator as a headwind. Most yachts cross somewhere between 25 and 30 degrees west. At the moment the ITCZ seems narrower than usual and is an area of light winds rather than massive windless lows, so we are keeping our fingers crossed that it stays that way and are planning to cross around 26 degrees west. At this point it is reasonably narrow but still far enough east to have a comfortable sail in the SE Trades.
The NE winds (known as the Portuguese Trades) that run down the coast of Portugal through the Canaries and as far as the Cape Verdes are formed by the squeeze between the Azores High and the pressure system over Africa. The true NE Trades are formed by wind rushing in to fill the low pressure that forms over the Equator. There must have been a bit of a gap between the two, because for the first two days we had light (5-8 knots) northerly winds instead of the forecast 15 knots north easterlies.
So we rigged twin headsails and ambled along, and although slow it was very pleasant sailing. We averaged a little over 3 knots on day 1 and covered 80NM. Day two 94NM. By early afternoon on day 3 a steady 15 knots plus NE breeze had set in and over that 24 hour period we covered 116NM. This was a great relief. With a boat like ours you work on an average of 100NM per day to calculate how long your crossing will take. So given that the distance between Brava and Salvador in Brazil crossing the equator at 26 degrees west is about 1800NM, you would expect our crossing to take about 18 days. This averages out the slow and fast days but Kath, works out that at 80NM a day it will take 22 days, and maybe even a month! (Kath's comment: I like to cover all eventualities, worst case scenario if we ran out of food is Franco would become a cannibal, not a good outcome for me!)
During the night Frontier Discovery, a cargo ship bound for Singapore (according to the AIS) passed 1NM astern of us. This is only the second boat we have seen on the crossing so far.
There has been a great deal of bird life; red footed boobies, Madeira petrels, and the amazing white tailed tropic bird. One of the latter circled so close that we thought it was going to land on the boat! We have also seen whole squadrons of flying fish and have had a couple of visits by huge pods of Atlantic spotted dolphins. The only whale sighting so far was too far off to be sure what type of whales they were. It was a large group of at least a dozen very large whales with a strong spout.