OMS

OMS SideStream Sidemount System (27 lb)

A minimalist sidemount harness with a redundant, manually-inflated backup air-cell and continuous webbing that adjusts to any torso length.

Wing / backplate

Modular harness and wing, the standard technical-diving setup. Expect to configure backplate, wing, and harness separately rather than buying a fixed jacket.

OMS SideStream Sidemount System (27 lb)
3.5Comparison Score
$459
Buy on Amazon
Released—
Stylewing backplate
Weight-integratedYes
Lift capacity27 lbs
Backplatenone
D-rings4
Trim pockets—
Material1000 denier anti-fray nylon, 2 in (5.1 cm) webbing, stainless steel D-rings
Travel-friendlyYes
Dry weight—
Fitunisex
SizesOne size (adjustable webbing fits any torso length)

"Lift capacity" is the manufacturer-rated buoyancy the wing/bladder can provide at the surface. Match it to your exposure suit, tank, and weighting, not the biggest number available.

Pros
  • Continuous 2 in webbing harness adjusts to any torso length without swapping hardware, and the split design needs no rigid backplate at all
  • Includes a redundant, manually-inflated backup air-cell with its own oral inflator and dedicated OPV, similar in concept to other redundant-bladder sidemount rigs
  • Spine-mounted weight pocket system holds up to 15 lb across three individual pockets, so most single-tank sidemount dives need no separate weight belt
Cons
  • 27 lb lift and no backplate option make it a dedicated sidemount rig, not usable as a backmount single-tank or doubles BCD
  • OMS does not publish a total system weight for the SideStream, unlike some competitors' sidemount harnesses
Diver community sentiment
Mixed opinions

An independent hands-on review praises the SideStream's build quality, price relative to competitors, compact travel-friendly size, and good trim from the first dive; its main criticisms are that the 27 lb lift (mostly non-ditchable integrated weight) is marginal for cold-water drysuit diving, and the manual backup inflator/dump valve are fiddly with dry gloves. A Scubaboard thread specific to this model surfaces a fit complaint: when the harness is adjusted for torso length, the bladder can sit too low to comfortably reach the oral inflator. A related older thread reflects some brand skepticism toward OMS generally.

JoeScuba: SideStream hands-on reviewScubaboard: SideStream 27 fit discussionScubaboard: OMS sidemount gear general discussion

Summarized from public forum discussion (Scubaboard, Reddit, and similar), not a survey we ran ourselves. See the linked threads for the original conversations.

The SideStream is OMS’s dedicated sidemount harness, built as a split-backplate system with continuous 2 in webbing that adjusts to any diver by resizing the strap rather than swapping hardware. It includes a redundant, manually-inflated backup air-cell with its own oral inflator and OPV, a buttplate with two offset cylinder D-rings plus two waist D-rings, and a spine-mounted weight pocket system rated to 15 lb. It’s built for cave, wreck, and technical divers running sidemount configurations rather than divers looking for a backmount single-tank or doubles setup.