PDA

View Full Version : Tides and Moon Cycles???



fraserfraser
03-12-2013, 07:50 PM
I am on Bonaire and there is more surge happening the last couple of days. i am told its because of the new moon.
any truth to that? looking at coming back next march and wondering if i should choose days that would have better odds of having benigh
dive conditions? what days would they be? being from the north east i do realize its good just to be here this time of year!

Anouk
03-12-2013, 08:12 PM
probably has something to do with it together with all kinds of other factors. Otherwise we would have this every month...

tursiops
03-12-2013, 08:26 PM
The moon does not affect directly affect surge, only tides. The surge is due only to waves flowing over bottom topography. If the tidal changes cause water depth changes in just the right way, the waves can be affected. Also, tidal currents can affect the wave field. But the tidal changes at Bonaire are pretty small, like 0.2m, with correspondingly small tidal currents. So, yes, the physics is there for the new moon to affect surge, but it is not likely.

A more common reason for surge to vary is waves coming from a great distance away...they are not high waves, but they have a lot of horizontal motion connected with them. This is what we saw during 21-28 Feb when we were there. No connection to the moon...

fraserfraser
03-14-2013, 01:55 PM
been going on too long for any new moon effect. maybe it has something to do with a storm in the gulf or...
anyway thanks for your thoughts. will just book for next march and take my chances. diving has been great anyway!:D

susan
03-15-2013, 09:37 AM
I'd say it probably has more to do with the upcoming spring equinox. That can also affect tides and water movements.