Diving with Steel 120s
Recently decided to add a couple steel 120s to my arsenal of dive equipment. The primary reason was due to some new wetsuits I acquired that are extremely buoyant (Henderson AquaLock 3 and 5mm). The 3mm suit required 14 lbs with an aluminum 80 tank. The 5mm was ridiculous. … Okay, okay, yes, … I’m making excuses but that was one of the excuses I used to convince myself to get the pair of 120s.
Making Up Excuses To Buy Dive Gear – Seems Normal
So I got them (bought them from Didier, owner of Go Dive Florida in south FLA #ShoutOut) and took them
to Boynton Beach and the keys for an initial trial. They not only reduced my added weight to 6 lbs (I think I could have gotten away with 4lbs) but they also extended my bottom time enormously. The transferring of weight to an item I required seemed to me to be very efficient. It was much better than adding weights to odd areas like tank straps or shoulder harnesses.
Your SPG vs. NDL
The extension of bottom time created an issue that must not be overlooked. Most of us will only look at the gas remaining in their tank on a typical dive. An aluminum 80 usually requires divers to ascend before they go past their no decompression limits. Not so for the steel 120s. With these you watch your NDL time rather than how much gas you have remaining on the typical recreational dive.
Comparison With Aluminum 80
The steel 120s are basically the same shape and diameter of an aluminum 80. They are a bit taller. Because they are steel they have a round bottom so they need a “boot” if you want to be able to stand them up. Boots are not my favorite accessory but with a steel tank they are a necessity for ease of handling. Not only do they allow you to stand your steel tanks up, they protect the bottom from scratches and dings.
One huge difference is weight. The steels are heavier than the aluminums and noticeably so.
Positives and Negatives
The positives about the new tanks are easy; transfer of weight to tank, and added gas range. The
negatives are, well, cost (unless you have some really good excuses) and weight. Although they are about the same size as an aluminum 80 they are easily 8-9 lbs heavier. And finally, because of the rounded bottom – you have to deal with boots on your tanks.
For the dedicated diver I think the positives will far outweigh the negatives. It also gives you another excuse to get your back in shape. That extra weight is noticeable on the boat when it is hanging from your back.
The Problem With Boots
The problem with boots is that salt water likes to get between the boot and tank. Popping the boots off of a tank can be a pain in the butt. Especially if you’re doing this after every dive trip. However, this is the price you pay if you want to keep your tanks from corrosion and a short life.
Removing the Salt
We already know that rinsing your tanks with fresh water after every dive protects the tank from corrosion. Additionally, everyone with boots on there tanks should, after every diving adventure, rinse the tank with fresh water with the boot off to get all the salt out of that area too. Then rinse and clean the boot before replacing it on the tank. Pain in the arse – yes. Good practice – yes. Will you regret it – no.
What About Buoyancy?
Oh, one more thing. Buoyancy! You may be wondering about the trim characteristics of a tank that is
slightly taller and 8-9 lbs heavier on your buoyancy. I’ll admit, the first couple of dives I had to make some adjustments but these were minor (such as placement of my BC on the tank). I had no problem adapting to the longer heavier tank and found the difference so slight it quickly became unnoticeable.
I have only dove eight times with my 120s as I write this. At this time I can consider the purchase well worth the price. These tanks do the two things I wanted done very well.