H-Valve or side mounted pony for wreck penetration

[VinceDS]

I will agree with several of the other posts above.

If you are looking at serious wreck penetration, at a bare minimum, you should be diving doubles. While valve failures are very rare, you want to be prepared if "Murphy" comes a knockin. If you are diving doubles, you will not need to worry about carrying a 40cf bottle, unless you are doing deco. Without knowing the depths you are diving and the conditions, it is hard to make a reccomendation based on a single tank and an additional bottle. My buddies and I routinely do penetration on wrecks in the 150' to 170' range, with a deco obligation, and are wearing doubles and 2 40cf deco bottles. With the deco bottles, they are worthless for backup air source as we cannot begin using them until we hit 70fsw. Just my .02 cents but you should go the doubles route...

 

[Marlinspike]

I agree with the prevalent view here: Niether H valve nor pony offer adequate gas supply for wreck penetration. If you are going to consider a proper penetration class, then take the time and money to do it properly - with doubles and an isolation manifold that offers true redundancy with access to a full gas supply. If you can't commit seriously, then I would suggest not doing it at all. It isn't worth the risk and there is plenty of ocean to dive without having to risk a wreck penetration without the benefit of proper gear, training, and the gradual accumulation of experience.

~Marlinspike