What are your favourite things to look for on Carribean night dives?
I would like to share tips on night diving in the Carribean as it is such a different experience than day diving and many people (sadly, including some instructors and DMs) don't know what to look for.
My observations:
*(cloudless) night dives with full moon are beautiful (and easier for a newbie to deal with) as the upper few metres of reef especially will be lit with the lovely glow. Turn off lights to fully appreciate silvery glow on shallow reef.
BUT:
*NO-MOON dark night dives are my favourite. (though not necessarily the best for a newbie to night diving, depending on their comfort level).
Why?
*coral FEED at night. Shine your lights on a brain coral and watch it 'explode' and eat the small worms attracted to your light. Very sci-fi!! The darker the night, the more 'worms' will be attracted to your lights to feed to the corals, so the worm-feeding thing doesn't really work when there is moonlight.
*ARROW CRABS, which are very common, will also eat the worms. They are rather inactive during the day but shine your light on one when there are worms about at night and watch them catch them and stuff themselves madly!! Crazy binge action!
http://www.stuorg.iastate.edu/marinebiology/tankphotos/images/DSC01346_JPG.jpg
*BASKET STARS come out and 'sit' on top of the reef. They undulate hypnotically when you shine a light at them and will also eat the worms by catching and 'exploding' them. Fascinating.
http://photography.nationalgeograph.../Images/Content/basket-sea-star-453472-sw.jpg
*OCTOPUS hunt at night, giving you a much greater chance of spotting one than during a day dive. Don't shine your light directly on them, they are sensitive! Enjoy their grace and beauty as they change colours instantly.
*If you are into NUDIBRANCHS, I saw many more nudis at night in the Carribean than during the day. Look on the purple finger corals in particular.
*Check out the STOPLIGHT PARROTFISH (very common), some of whom turn brilliant turquoise at night and wrap themselves in a mucus 'bed'
http://hawaiimarinelife.com/images/uploads/Parrotfish_at_Night.jpg
*PHOSPHORESCENCE: another reason why no-moon night dives are more spectacular. The darker the sky, the more dramatic the phosphorescence will be when you turn off your lights. Leave them off for at least 5 mins or more to let your eyes adjust to the dark and enjoy the starry night/wizard effect all around you. Do this over a sand patch if you are unsure about your buoyancy at night in the dark.
*STRING OF PEARLS!!!! I don't know if they have this all over the Carribean because I only did night dives on Roatan and Utila in Honduras but there, in addition to the phosphorescence, if you turn off your lights and let your eyes adjust, you will start to see something that looks like a beaded curtain of lights in a line, descending vertically. Then you will notice it everywhere, millions of lights around you everywhere, without having to agitate the water. Stunning. You MUST dive on a moonless night and let your eyes adjust for quite awhile to see it, and there must be no current. Stay immobile for awhile to spot it as the phosphorescence stirred up by movement will distract your eyes. But what is it, exactly, you ask?
It is the mating display of ostracods (tiny crustaceans, about the size of tomato seeds). Male ostracods release their bioluminescent chemicals into the water as a string of dots. The spacing of the dots in the water is unique to a particular species so females, recognizing the code for their own species, can swim to the end of a string of dots and know that they'll find an eligible male. (Explanation by Dr. Edith Widder - Director, Bioluminescence Department Senior Scientist Harbor Branch Oceanographic Institution)
In general, go slow, and take the time to check out the different critters on the reef that you won't see during the day, such as BALL CORALLIMORPH, SPINY URCHINS (much more visible as they come out fully at night--check out the mysid shrimp that sometimes swim within their spines!) and more. Enjoy! And give me your own tips and observations!
I would like to share tips on night diving in the Carribean as it is such a different experience than day diving and many people (sadly, including some instructors and DMs) don't know what to look for.
My observations:
*(cloudless) night dives with full moon are beautiful (and easier for a newbie to deal with) as the upper few metres of reef especially will be lit with the lovely glow. Turn off lights to fully appreciate silvery glow on shallow reef.
BUT:
*NO-MOON dark night dives are my favourite. (though not necessarily the best for a newbie to night diving, depending on their comfort level).
Why?
*coral FEED at night. Shine your lights on a brain coral and watch it 'explode' and eat the small worms attracted to your light. Very sci-fi!! The darker the night, the more 'worms' will be attracted to your lights to feed to the corals, so the worm-feeding thing doesn't really work when there is moonlight.
*ARROW CRABS, which are very common, will also eat the worms. They are rather inactive during the day but shine your light on one when there are worms about at night and watch them catch them and stuff themselves madly!! Crazy binge action!
http://www.stuorg.iastate.edu/marinebiology/tankphotos/images/DSC01346_JPG.jpg
*BASKET STARS come out and 'sit' on top of the reef. They undulate hypnotically when you shine a light at them and will also eat the worms by catching and 'exploding' them. Fascinating.
http://photography.nationalgeograph.../Images/Content/basket-sea-star-453472-sw.jpg
*OCTOPUS hunt at night, giving you a much greater chance of spotting one than during a day dive. Don't shine your light directly on them, they are sensitive! Enjoy their grace and beauty as they change colours instantly.
*If you are into NUDIBRANCHS, I saw many more nudis at night in the Carribean than during the day. Look on the purple finger corals in particular.
*Check out the STOPLIGHT PARROTFISH (very common), some of whom turn brilliant turquoise at night and wrap themselves in a mucus 'bed'
http://hawaiimarinelife.com/images/uploads/Parrotfish_at_Night.jpg
*PHOSPHORESCENCE: another reason why no-moon night dives are more spectacular. The darker the sky, the more dramatic the phosphorescence will be when you turn off your lights. Leave them off for at least 5 mins or more to let your eyes adjust to the dark and enjoy the starry night/wizard effect all around you. Do this over a sand patch if you are unsure about your buoyancy at night in the dark.
*STRING OF PEARLS!!!! I don't know if they have this all over the Carribean because I only did night dives on Roatan and Utila in Honduras but there, in addition to the phosphorescence, if you turn off your lights and let your eyes adjust, you will start to see something that looks like a beaded curtain of lights in a line, descending vertically. Then you will notice it everywhere, millions of lights around you everywhere, without having to agitate the water. Stunning. You MUST dive on a moonless night and let your eyes adjust for quite awhile to see it, and there must be no current. Stay immobile for awhile to spot it as the phosphorescence stirred up by movement will distract your eyes. But what is it, exactly, you ask?
It is the mating display of ostracods (tiny crustaceans, about the size of tomato seeds). Male ostracods release their bioluminescent chemicals into the water as a string of dots. The spacing of the dots in the water is unique to a particular species so females, recognizing the code for their own species, can swim to the end of a string of dots and know that they'll find an eligible male. (Explanation by Dr. Edith Widder - Director, Bioluminescence Department Senior Scientist Harbor Branch Oceanographic Institution)
In general, go slow, and take the time to check out the different critters on the reef that you won't see during the day, such as BALL CORALLIMORPH, SPINY URCHINS (much more visible as they come out fully at night--check out the mysid shrimp that sometimes swim within their spines!) and more. Enjoy! And give me your own tips and observations!
