The traditional tec BC is a metal backplate, an air cell — also called a wing — and a harness made from 2-inch webbing. This configuration is still preferred by many techies, but adjustable shoulders with quick-release buckles and integrated weight systems are now common on modern tec rigs. There are even soft backpack designs built to carry the load while providing more comfort. Here are five systems that run the gamut from basic to Cadillac.

Apeks WTX SeriesThe WTX system is modular, and our test system consisted of a WTX harness, stainless-steel backplate, WTX4 air cell and a pair of SureLock integrated-weight pouches. The WTX Harness is made of tough 1,050-denier ballistic nylon reinforced with 2-inch webbing, and an internal sleeve accepts the backplate for bolting on doubles. A thick back cushion attaches with Velcro and six 2-inch and eight 1-inch D-rings provide attachment points for extra gear. The WTX4 air cell is a double-bag design with the abrasion-resistant outer bag is made of 1,000-denier Armorshield Cordura. It provides 45 pounds of lift and offers a lower-left exhaust valve and optional right exhaust port. Performance: Test divers used the WTX system with doubles using the backplate, with a single using the backplate and with a single without the backplate, proving that you can take this rig from full tec to tropic and anywhere in between. There’s a wide range of easy adjustment in the harness, allowing you to change from wetsuits to drysuits. The SureLock weight system fits neatly on the waistband and brings one of the best integrated-weight systems from recreational diving into the tec world. WTX Harness, $345; stainless-steel backplate, $174; WTX4 air cell, $325; SureLock system, $135 www.aqualung.com | | Dive Rite Nomad EXPWhile this rig is tailor-fit for side-mount configurations and rebreathers, we found it works just fine with a set of doubles or a single cylinder. Our test unit came with a 60-pound-lift single bladder and the semirigid backpack extends downward to include a butt plate that offers attachment points for side-mount cylinders and a crotch strap. Grommets in the center of the backpack offer easy bolt-on mounting of doubles with optional stability plates, or a single cylinder can be worn with dual soft-tank bands. Bungee cords keep the top of the air cell streamlined, and shoulder straps are routed over the top of the air cell to further control air volume. Eight 2-inch D-rings provide ample attachment points. Performance: Back-mount or side-mount, singles or doubles, you can dive them all. When we mounted up our double 100s, we were surprised at how stable they were. The semirigid backpack, reinforced with 2-inch webbing, is definitely up to the task. The shoulders are wide and supportive, and the retention system of bungees and straps keeps the air cell well contained. It’s an excellent choice for divers who use a variety of tank configurations. $699 www.diverite.com

Hollis Backplate SystemOf the systems reviewed here, the Hollis Backplate is the most basic and for purists perhaps the best choice. It consists of a stainless-steel backplate with grommets for mounting doubles and slots to accommodate bands for a single tank, a 45-pound wing and a solo harness system. It comes with padded shoulder covers that slip over the webbing for increased comfort, eight 2-inch stainless-steel D-rings and a crotch strap. The air cell is from Hollis’ new C-Series, designed with a 360-degree bladder for streamlining and balance. The air cell is made with an outer shell of 1,000-denier Cordura and a 15-millimeter-thick urethane internal bladder. It has a centrally located inflation hose elbow and an exhaust valve on the lower left. Performance: While it takes a little time to get the rig adjusted just right, once you dial it in, it stays there. Initial test dives were with double 100s bolted to the backplate, followed by dives using soft bands for a single cylinder. In both configurations the rig felt snug, stable and completely free of any bulk or clutter in the torso. Inflation control was smooth and efficient too. In short, going simple still works pretty darn good. Stainless-steel backplate, $157; C-45 wing, $273; Solo harness, $89 www.hollisgear.com | | OMS B.Y.O.B.S (Build Your Own Buoyancy System)This rig is modular and customizable. We started with the IQ Pack harness and a 32-pound-lift air cell for use with a single cylinder. The IQ Pack is made of 840-denier nylon and reinforced with 2-inch webbing. The backpack provides a sleeve to accept a metal backplate for doubles. A thick pad covers the mounting hardware and provides extra comfort. Shoulders are overlaid with 2-inch webbing that can be easily opened to add additional D-rings or adjust length. The system also has quick-release adjustable buckles, a dual-adjust sternum strap and a crotch strap. The air cell is made of 1,000-denier nylon with a 210-denier nylon bladder. Performance: We set it up as a soft pack with a single tank and in minutes could have added a plate, a larger wing and bolted on a set of doubles. The harness is secure and comfortable, and the 32-pound air cell is compact. Shoulder adjustments are quick and easy with weight keepers used to secure webbing and D-rings. The OMS system seems well suited for the tec diver who also occasionally goes rec, because it’s so easy to switch out components to match the mission. IQ Pack, $361; 32-pound air cell, $392 www.omsdive.com

Zeagle Tech-10The Tech-10 is a new soft backpack BC designed for “extreme duty,” according to Zeagle. Made of rugged 1,050-denier ballistic nylon, the Tech-10 comes with dual soft bands to accommodate a single tank, as well as mounting grommets for doubles. The rear air cell provides 65 pounds of lift, and its ripcord integrated-weight system holds 36 pounds in front pouches and 20 pounds in rear trim pouches, all ditchable. The rig has an extrawide waist panel with dual waist straps that provide a lot of midsection support. It also comes with a split-saddle-style crotch strap and utility pockets. The inflation system comes with a streamlined power inflator plus two lower dump valves. Performance: We like the travel possibilities of the Tech-10. As a soft backpack system, it travels lighter than a backplate rig yet still gives you all the attachment options for hooking on additional gear. We tested the Tech-10 with both a single tank and a set of doubles, and it supported both loads well, and you can also rig for side-mount. The wide waist section with twin double-pull buckles makes the rig supersupportive and extremely stable underwater. Tech-10 with standard BX-Inflator, $789; with an Octo-Z (Inflator/Alternate Air), $929 www.zeagle.com |