Todd Kwon-Do

How do I love thee?

At this time tomorrow, I should be underwater in Fort Lauderdale exploring the wreck of the Captain Dan. The "Dan" was a 175' Coast Guard buoy tender that had several owners before it was sunk as part of Florida's artificial reef program. She rests in 110' of water... a significant depth to be sure. Recreational Advanced Open Water certifications prepare divers for maximum depths of 120', however it's rare for most people to venture beyond about 70'.

The "Dan" is the first of about eight dives that we will do in the next two days. For people that don't scuba dive the fears always involve sharks, or running out of air. However, the fact is that the real dangers in diving all revolve around things you can't see until it's too late; nitrogen narcosis, air embolism (the "bends"), and oxygen toxicity are just a few of the dangers you have to be careful to avoid.

The reason that a lot of people don't go beyond 70' is that your body absorbs lots of nitrogen under pressure and the "bends" become a real possibility. So, you have to limit the amount of time that you spend at deeper depths. For lots of people, the risk associated with "going deep" for 3-7 minutes of time to explore doesn't make it worth the trip.

One way to extend your bottom time, and be safer when diving, is to use mixed gasses. Instead of breathing normal compressed air like most divers (which contains 21% oxygen), you can use a higher percentage of oxygen or even a complex gas called tri-mix. This kind of technical diving can extend your range, but it comes with it's own risks.

When we descend on the Dan tomorrow, my wife and I will be breathing a Nitrox mix which contains a higher percentage of oxygen than normal air. It makes us less susceptible to the "bends". The trade off is that if we calculate the mix wrong, fail to properly monitor our dive times, or don't keep track of the volume of mix that we breath, the oxygen in our systems can actually become toxic and kill us (wierd huh?).

Of course there are lots of things that will work to keep us safe. There is the fact that we are both trained in this type of diving, we will also be monitoring each other (as well as ourselves) during the dive, and then there is also our most important tool... our computers.

We have little waterproof computers that we dive with that are attached to our air systems and ourselves. These little guys (when properly programmed) will monitor how many breaths we take, our depth, the pressure in our tanks, and the percent of Nitrox mix we are using. They will track our depth every .5 seconds and will recalculate our oxygen exposure, nitrogen absorption, and other factors, and then they will use that information to keep us safe. They will tell us when and how to surface so that we have appropriate "decompression" times at specific depths that they will calculate on the fly.

Basically, we need these computers to stay alive.

So, how much do I trust my little computer? Not that much!

I carry three of them.

As long as they are all telling me the same thing, I know I am OK. I have been laughed at by other divers on the boat for having more than one with me, but I feel good knowing that I am not betting my life on a single piece of equipment, or a single manufacturer.

The bottom line is that I believe in redundancy, which is a lesson that NASA learned this week when the computers on their space station got a virus.... AGAIN!

NASA announced this week that the computers on the space station had spyware on them that was designed to collect account information and transmit it back to a server on the Internet. They also announced that this was not the first time they have had this problem up there.

Down here on Earth, our engineering team is dealing with the same problem every day at our client's offices by applying what I have learned while diving. We count on several layers of virus protection to keep us safe from the bad things on the Internet. That redundancy helps me and my client's sleep well.

A good virus strategy has at least four layers. Information is scanned at the SPAM filter, on the mail server itself, at the border of the network by the firewall, and finally at the workstations and servers. Like my dive computers, we try and use different manufacturers at each level so that we get the benefit of different "points of view" when scanning for viruses. Again, redundancy saves the day!

To all of you I say that you should take a lesson from my dive computers, or learn from NASA's mistake, so that you don't have to suffer the humiliation of calling your computer guys to come clean a virus out of your network.

Remember, you have been warned! :)

Ok... I am off to check over my gear and prepare for tomorrow's festivities!

posted by Todd @ 4:32 PM