Travel BC vs Std BC for regular diving?

[halocline]

At the surface, fully loaded (full tank), one should be neutral with a lung full of air, and an empty BC. Lift capacity of the BC should be an non issue. We then add a couple of lbs to account for the empty tank at the end of the dive.

This isn't quite right. You want to be neutral at the surface with an empty (500PSI)tank and a normal breath. This will make you negative at the onset of a dive by the weight of air in your tank. You can't really check weighting with a full tank. You can estimate, but that's it. Technically, you want to be neutral at 10-15ft with a near-empty tank, which would allow you to do a safety stop and possibly make you slightly positive at the surface. This distinction is rarely more than a lb or 2.

In general though, if I understand your question, it's something like "If I never need more than 25lbs lift, why should I buy a BC with 35lbs" and the answer is, you shouldn't. Ideally you want to have just enough lift, maybe a little safety margin, but too much lift is an annoyance and possibly dangerous. IMO most rec divers use BCs with way more lift than they need, part of the unfortunate attitude that "a BC is a life preserver" promoted by the design of many jacket-style BCs.

If you search for Tobin's (cool hardware) posts on calculating lift requirements, you'll find that he really has down to a science.

 

[Mortis65]

Mattboy,

Thank you, That is exactly the question that I was trying to ask, and you gave me the answer that I was expecting, but was trying to confirm.

I appreciate someone else's thoughts about needed a lot of extra lift in a dry suit, if the suit sprung a leak or such, but for the time being, I plan to stick to a wetsuit.

Thank you everyone for thoughts and suggestions.

Mortis