It seems that's all the charter will supply me with for a dive.
Are there not charters that set divers up with a something for a little longer BT?
most of our wreck dives are double dips these days, allowing the recreational diver 2 dives and anyone else to do a longer dive within their level of qualification, experience and personal comfort, up to a max of about 2.5hrs on a regular 'double dip' trip.
As for tanks, I allow anything you care to use as long as you dont use an additional bottle (pony, stage, deco, sidemount, etc) as back gas to extend your bottom time if you are not qualified to do so. This means rec divers are welcome to take as much redundancy as they like and tech divers can take whatever back, stage & deco gas they require for their profile, level of training and comfort.
I rent double AL80's with Halcyon DIN manifolds and Highland Mill bands, AL40 & 80 stage and deco bottles with Halcyon rigged stage kits, and HP worthington steel 130's again with Halcyon manifold and highland mill bands.
For the recreational diver, I also have steel 100's and 120's.
Check out our WreckFest event, the biggest ocean tech dive event in the country, where there will be dozens of all types and sizes of OC and RB tanks being used on the boats, with every type of profile, deco model, computers, tables etc being run.
Silent World: Wreckfest