The Season

hurricane

The diving season in New Jersey begins in June for most of us. Hardy souls in drysuits will dive all year long, but with a good 7mm wetsuit, early June is still chilly. By late July the ocean has warmed up nicely, and it keeps getting warmer through September and doesn't really get cold again until October or even later.

So the peak dive season is June through November, right? Well, not quite. Early August starts hurricane season, and by late August it is in full swing. A couple of good storms and everything is so roiled up that there is almost no point in trying to dive anymore. That's not to say that there can't be a good year with no hurricanes. Barring storms, with a drysuit you could reasonably expect to dive from late April to early December.

Monthly surface water temperature data from the Long Island weather buoy (44025). Bottom temperatures are considerably lower in the summer months.


Human Vision Underwater

When light travels from a less-dense medium like air to a more-dense medium like water, the rays are refracted or bent towards the normal or perpendicular of the surface between the two mediums. In crude terms, light going from air to water will tend to be straightened, while light going from water to air will tend to be ... um ... crookeded. Confused yet? Take a look at the figure below.

refraction
( Tautogolabrus adspesus )

In this figure, you can see the light rays traveling from an object in the water to your eyes, neglecting the effect of the flat glass lens of your mask. The blue lines trace the actual path of the light rays through the water and into the air, or conversely, through the air into the water - the direction really doesn't matter. As you can see, the rays are bent toward the perpendicular of the surface on the water side, and away from it on the air side.

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