Full moon, high tides and best diving

[scubachild]

Hi there

Can anyone give me some advice as to the relationship between tides, the moon and best diving conditions? I have been looking at a program called WXTide32 a free windows tide and current program. It shows high tides not only at full moon (as I would expect) but at new moon as well. Can this be correct? What are all the factors that effect high tides? Are low tides the best time for good visability?

Thanks for any help!
Hsappy Diving
Adam
scubachild@hotmail.com

 

[under water]

Adam, Most everywhere there are two high tides every day.
See this http://en.wikipedia.org/wiki/Tide for a good overview of the relationship between moon, earth & sun to form the different tide patterns.

 

[Charlie99]

The link Frank posted is very good detailed info on tides.

Some key items relative to diving ----

The highest tidal RANGE (difference between high and low tide) is around both new and full moons. The highest high tides and the lowest low tides. "Slack tide" or the period of little tidal generated currents will be shortest.

The lowest tidal range is around 1st and 3rd quarter --- about 1 week before and after the new moon and full moon. Currents due to tides will be smallest.

Tides will come about 50 minutes later each day, which is also about 6 hours later each week.

For night dives, I prefer around 1st quarter. Around first quarter, the moon will be well up in the sky at sunset and provides lots of light.

The tide tables and programs don't have many places for where they predict currents, so often you will have to just estimate by having observed before that slack current was xxx minutes or hours before or after high tide. There are lots of factors that will change the actual time of slack water, so any prediction should be treated as merely a guess, and you should watch the water and carefully choose when you start the dive.

If you are diving at the inlet to a bay or river, generally the slack tide near high tide has better visibility, since the inlet will then be filled with water that has come from the ocean, which generally has better visibility.

For night dives, around 1st quarter is a nice moon phase. Around 1st quarter (midway after new moon and before full moon) the moon will be high in the sky at sunset.

 

[under water]

Charlie,
You should add that great description about diving & tides to the wikipedia entry.