Some regulators come with adjustable second stages. This is usually in the form of a knob to rotate or a lever to slide. First of all, this serves two purposes:

1. It allows you to adjust the sensitivity of the air flow, making it harder to free flow. If you are in a strong current at the surface, for example, your second stage might normally be inclined to free flow.
2. As the service date approaches, the performance of regulators decreases slightly. This may mean it requires more energy to pull air from the second stage. An adjustable second stage allows you to "open it up" during this time, maintaining a steady performance.

You may be tempted to use the adjustment knob to limit air flow in an attempt to save air. This is a bad idea.

First of all, it won't even work. If it requires more energy to breathe, you are going to end up needing more air than you would otherwise. Secondly, limiting your supply of oxygen is always a bad idea.

To use an adjustment to extend your air supply, do just the opposite. Open it up so that air is supplied to you with minimal effort. Remember, relax!

Note: This post applies only to males.

I always see male divers wearing bathing suits or board shorts under their wetsuits. This requires awkwardly stuffing all the excess fabric into the wetsuit legs, and not to mention, the suit tends to ride up. I did it once for my Open Water certification and hated it.

There are options, however. Even if you would never wear it otherwise, I highly recommend wearing some kind of form-fitting lycra swim material. This doesn't have to be the legendary Speedo briefs; I wear something similar to these Speedo jammers and think they're great. You …

I went to a local dive store this morning and picked up one of these neoprene mask strap covers. As soon as I got home I put it on my mask. Sitting in my kitchen with bone dry hair the mask slipped on and off painlessly.

This should prove incredibly useful, especially as I begin my divemaster training, where I will constantly be removing and replacing my mask. I wish I had bought one when I originally purchased my mask. I couldn't find a plain one with no words or pictures, so instead put it on my mask backwards where …

One of the first purchases I made after becoming Open Water certified was a point and shoot camera (Canon PowerShot SD1100IS) and an underwater housing. I enjoy taking pictures in "real life" and wanted that to carry over into diving. A lot of my pictures really sucked, though, and I wanted to get better.

Unfortunately, I found a lot of the information on the web is for expensive SLR cameras, with tips pertaining to things like aperture settings and strobe placement---not things relevant to my little cheapo. As a result it's taken me a while to figure out some of …

Communication underwater can be a problem, and is usually restricted to a small set of hand signals. It can be even more challenging to get the attention of your dive buddy, however.

It happens to me all the time, I see something really cool, but my dive buddy is looking in the completely opposite direction. Unless I'm within reach, I have no way to get their attention. This articles addresses presents our options for making noise underwater.

Commercial options

Many stores would be glad to sell you a remedy. Here are a few common choices:

• Shaker / Rattle

  

  Probably the most …

Recently in Mexico, a woman gave me an account of a recent dive in Honduras. In this dive, the dive leader brought a bucket of chum (various fish parts). He would pull the fish parts out of the bucket and feed them to a swarm of sharks directly in front of the dive group. This gave the divers an up-close view of these amazing animals.

A similar story is told in a recent New York Times article. This time, the story takes place in Fiji. The author casually talks about the dive leader, who goes so far as to call …

It's never any fun when your dive gets cut short because your buddy's air is low.

It's even less fun when you're that buddy.

Want to make your air last an hour or more? Read on to get the tricks all the top divers use.

First off, keep in mind what it means to make your air last. You don't necessarily need it to last an hour, all you need is to make it to your decompression limits. For instance, that's just 40 minutes for a 66ft/20m dive (following the PADI recreational dive planner). Reaching some of these limits …

Here are some stunning photos of a 14ft great white shark. I don't think I have ever seen a diver this close to a white shark outside of a cage!

The photographer is Amos Nachoum, who is known for his close encounters with large creatures both above and below the sea. In fact, he takes tourists on expeditions to experience big animals up-close and in person. I, for one, would love to drop in the water during the famous Sardine Run off the coast of South Africa, or swim up close with a blue whale.

We all know the importance of a buoyancy check. Even if you manage to descend, poor buoyancy affects your body's profile in the water, decreasing the overall quality of your dive. Effective air consumption, good ascent / descent control, and an effortless dive all depend on a streamlined position--which can only be achieved with proper weighting.

Despite these facts, rarely do we check our buoyancy. Divers are not entirely to blame, most dive outfits never give us the opportunity in the water, instead rushing the group to depth as quickly as possible.

Next time you are in strange waters, or have …

While diving last week I realized how poorly most divers check their regulator. Thoroughly testing your regulator takes less than a minute, and greatly eases my mind before a dive.

First, I see a lot of divers check their primary by pushing the free flow button. This is insufficient for me. I prefer to take a breath or two off of the regulator, which ensures air is pulling properly through the hoses and diaphram, not to mention avoids wasting precious air; air comes out fast during free flow!

The second oversight is one I am particularly guilty of. Many divers …