I have the Mares Cruise X strap. Good bag for single tank diving and those that like to streamline their gear. Looks like you’re a technical diver....this bag probably won’t provide adequate space. The only drawback of the X Strap bag is the shoulder straps are a little long and this make the chest strap pretty worthless. So the bag, even when fully loaded, tends to droop a little versus riding smartly on one’s back. Once all your gear is out, the bag collapses nicely for stowage on a small boat.
The Mares Cruise Backpack is my bag for technical diving and travel. It has been across the Atlantic and through European airports several times, dragged mercilessly up and down my villa stairs at least 175 times, heaved into the back of a SUV with bare twin tank bolts poking up, gone for weeks with salt stains around the zippers....in short, there isn’t any abuse left that I haven’t dished out to this bag. The back unzips and out pop the shoulder straps for carrying it properly up and down stairs. The dedicated fin pockets on the side are long and large enough to fit one’s rock boots preserving internal space for your oversized reg bag and other technical kit. It’s a structured bag but not overly structured. It’s fine on a liveaboard where one can stow the bag on the sundeck but it’s a little too big to keep in a berth-only cabin and on a small boat (like a 6-10 diver boat) since it doesn’t collapse down much.
Great bag, IMO. When this one blows up, I’ll get another.