Sunday, December 20, 1998 – Off the coast of Nicaragua
G’day Star-trippers
First I would like to welcome all the new cyber-sailors that have joined us over the last few days. Your support and kind words are very welcome. We download our email every six hours and it is always a pleasure reading all of your missives, short or long.
The weather has turned somewhat worse over the last 24 hours. Who is responsible for this I do not know? It was ever such smooth sailing and now we are either banging head-on into these short and nasty waves or taking them broadside, which is a little more comfortable, as the stabilizers take care of that. Still beats the Christmas rush on Oxford Street any day though. Our speed also has not been the fastest to date. We have been averaging at most about 9.5 knots and as I speak we are moving along at a snails pace of about 6.5-7 knots. We therefore anticipate pulling into Puntarenas no earlier than late tomorrow evening rather than early afternoon as hoped.
An extraordinary thing has been happening of the last three nights. DJ has been waking me up at 04:00 for my watches every night so far, and every time I get onto the skipper’s chair, dolphins make themselves heard as they ride our bow wave. What a better way to be greeted at such an unearthly hour than by our cetacean friends. Nighttime is particularly fabulous as the dolphins are covered in and give off streaks of bioluminescence as they dance the night away. If you have never seen this phenomenon, imagine sparkles, pulses, bands, wheels, and blobs of light that erupt as the dolphins swim through the water. I found a rime that may explain it even better:
About, about in reel and rout
The death-fires danced all night,
The water, like witch’s oils,
Burnt green, and blue and white.
Extract from The Rime of the Ancient Mariner by S.T. Coleridge
So what is it? Well, bioluminescence is a cold light, which is emitted by all sorts of organisms both marine and terrestrial. In the oceans, species such as bacteria, dinoflagellates (algae with whip like "hairs" for swimming), invertebrates and vertebrates are known to give off this cold light. In our case, the light is given off by certain organisms such as jellyfish, siphonophores and ctenophores that have been agitated either by the boat or dolphins moving through the water. These invertebrates will shed luminescent tentacles or puffs of glowing fluid in order to distract what they deem as predators. Many other marine organisms do similar but for different responses and reasons such as communication, camouflage, seeing in the dark (e.g. deep water), feeding and even reproduction. How the light is produced is not understood completely, but in short it is a biochemical process where by certain organic compounds are oxidized.
Dolphins at the bow yesterday during the day
So there you have it. I guess this journal sets the scene a little for what is to come once John McCosker comes on board and we get to Cocos Island. Prepare yourself for some breathtaking underwater pictures and some good down to earth science and fun to go with it. Until tomorrow I wish you all well.
Rich