From Day to Day

The North Atlantic is extremely changeable. The aspect that most governs where and when you will ( or even can ) dive is the wave height or the surf. If the surf is pounding on the shore, then it is a good bet the inlet will not be a good dive, let alone the beach. A big surf will even ruin conditions way up the river, say at the Railroad Bridge.

The wave heights on the open ocean will dictate your boat diving. In 1-3 foot seas, the boats can go just about anywhere, all the way out to even the farthest wrecks. In 3-5 foot seas, some boats will do that anyway, but don't count on it. Instead, a closer-in site will be your most likely destination, although perhaps as far as the Pinta or the Mohawk. In 5-6 foot seas you are going to the Delaware, and you'll wish you'd stayed home. Bigger waves than that, and you shouldn't even leave port, although some captains will try. While this may seem like admirable determination on their part ( more like irresponsible greed in some cases! ) you're better off just not going.

So how can you tell if it's a nice flat day, or a sickening 5-foot chop and roll? You really can't, not without being out there. Elsewhere, I have placed links to the marine forecast for the area, but that tends to be less than usefully accurate, and sometimes grossly in error. The regular weather forecast is useless beyond a one or two-day projection, and that doesn't tell you much about the sea state.

Fortunately, there is some predictability in the conditions over the course of the day, from morning to night.


A Jon line is a cord used to secure yourself to the anchor line during your safety or decompression stops. This relieves you of having to hold on by hand, which can get tiring for long hangs in a strong current. You can also use a Jon line to get away from the crowd at 15 ft, while still being securely tethered to the boat.

There are a number of prefabricated Jon lines on the market that you can buy, along with several different gadgets to attach it to the anchor line, most of which are clever but not particularly reliable. For a few dollars, you can build a much better Jon line with parts from the hardware store. What you will need is:

  • 6 ft of bungee cord - the kind with a fabric casing
  • 2 brass snaps
  • 6-8 wire ties

Printed from njscuba.net