Hollis SMS75 Review, Setup and Modification

Hollis SMS75

When people hear sidemount today they often think of 2 companies that have been dominating the market share, the Razor sidemount and the Stealth sidemount systems.  I must disclose that I have never dove the Stealth sidemount system but I have owned and dove the Razor 2.0 complete system.

Let’s get a few things out of the way, the Razor and Stealth systems are both extremely streamlined and take up a small footprint. The Razor offers their batwing which is a dual bladder setup (very nice for redundant lift capabilities).  The Stealth has a similar design however it is lacking a dual bladder (one can be added but it is not standard).  Both Razor and Stealth systems utilize webbing material and metal brackets to form a harness, there are no fastex quick-release style buckles.  The upside to this design is that there are less points of failure and they offer a completely custom fit.

The SMS75 is a more traditional style system in that it is closer to a traditional bcd versus a sidemount harness.  To some this may be a fault, however I believe this is hands down where the SMS75 will make its money.  The harness style systems take significantly longer to setup and fit.  For a comparison it took me about 2-3 hours to setup my Razor to factory specifications where it took 5 minutes to setup my SMS75.  This is critical for shops that sell to primarily open water sidemount divers.  I think that the primary marketshare for beginning sidemount divers will be dominated by the SMS75.  What customer wants to spend that much time  setting up gear when they first get it?  Sure I will I agree that technical divers will most likely enjoy the über customization that can be achieved by the Razor / Stealth, and those same people will argue that the Razor offers true lift redundancy.  I will argue that none of these systems is perfect.

The Good and the Bad

Let me first say this, I am NOT a cave diver and I have no cave experience so my perspective is from open water sidemount, not cave/wreck penetration.

The Bad

1. Size: The first thing that you notice (especially if you have owned any low profile harness like the Razor/Stealth) is that the SMS75 takes up a large footprint and it appears bulky.  While Hollis has slimmed down this new bcd from the SMS100, the SMS75 is still large in comparison to other sidemount rigs.  The SMS75 is more along the same size of a traditional travel size bcd.

The Fix: I’m not sure I would fix this based on what this tradeoff provides the diver.  While the bcd is large it does offer some unique characteristics that are unparalleled in other sidemount only bcds.

2. Vent Placement: The SMS75 has only 1 overpressure relief/dump valve.  While this itself is not a bad thing the placement is.  Factory setup has the dump valve at the top left shoulder which does cause some extremely mild discomfort when wearing it with only a rash guard (it is just enough to let you know it is there, not painful).  The problem I have is with the fact that it doesn’t vent toward the surface if you are in a proper trim position for sidemount.  The vent exhausts into the upper shoulder meaning the diver has to put him/herself into a head up position slightly.  Thankfully the placement isn’t so bad that trim is completely lost, it is just requires a less than perfect trim position to vent.  I suspect that this is because the inflator/deflator can trade places with the vent to provide a recreational style location where the inflator/deflator comes over the left shoulder (discussed in “The Good”).

The Fix: in the next version of the BCD, Hollis could simply put a second vent at the lower tail facing away from the diver.   The current placement of the shoulder vent could be moved up away from the shoulder and more on the upper back facing away from the diver, not venting into the diver.

3. Redundant Lift Capability: There is only a single bladder version at the moment.  For serious tec divers that will be carrying weight that requires a dual bladder setup this bcd will fall short.

The Fix:  I would suggest a bare-bones 2nd bladder that is sandwiched like the Razor system.

As with all sidemount harnesses I had to make some minor modifications to achieve perfect trim.  Ideally I would request that a round ring system that I describe below be part of the factory kit.

The Good:

Can the SMS75 recover from those negatives listed above to make $700 (MSRP) worth parting with?  I would say yes…hands down.  Why?

1. Versatility: The SMS75 is a great multi-system that can be used as both sidemount and backmount diving; and very quickly.  It only takes about 5 minutes (taking my time, careful not to strip the plastic threads) to switch between sidemount and single backmount.  All a diver has to do is swap the inflator/deflator and exhaust vent.  This is especially valuable to instructors and dive shops now that major training organizations allow for training entry level students in sidemount diving.  If a shop/instructor had these as rental units they can train both sidemount and traditional backmount students…no need for 2 systems, the SMS75 can do both.

2. Insanely FAST setup:  This sidemount system has an unparalleled minimal setup time.  Literally you can dive this system right out of the box in under 10 minutes.  This even includes setting up the tank bands for the tanks…maybe 20 minutes if you have to watch the YouTube video several times to get the tank band setup correctly.  It took me roughly 15 times longer to setup the Razor sidemount system.

3. Quick Change from Cold to Warm Water and Back: This is another great feature of this system over all of the rest, especially for those of us who don’t get to dive in bath water all year round.  Diving here in South Korea we dive dry suits with heavy undergarments almost all year; when we get to dive in the tropics we have to change our harness setup for much less thermal protection (if any).  On the Razor system this took about 30-60 minutes…with the SMS75 it can be done in 3 minutes.  What’s not to love about that?

Overall this is such an excellent and versatile bcd that I have convinced most of those that know me to order one.  I really had to work hard to find some complaints with this bcd.  Even with being hyper-critical I would buy the SMS75 again as well as recommend it to anyone who would like a great sidemount harness but isn’t quite ready to completely go sidemount all the time.

Check out the Hollis SMS75 Open Water Performance Review

What I Had to do to get the SMS75 to My Personal Standard / Liking

Hollis SMS75 waistband round-ringsBoth the Razor and the SMS75 needed (in my opinion) minor modifications in order to be an excellent harness.  To make matters even more close they both (and the Stealth would be included in this if I had owned one in the past) needed the exact same modification.  The modification mimics the DiveRite Nomad bungee system.  It was the addition of 2 – 2″ metal round rings (not “D” rings) in the middle of the bungee on each side.   Since the SMS75 comes with some really nice side bungees you will definitely want to reuse these.

  1. unhook the quick link from the bungee
  2. loop the bungee over the round ring to form a girth hitch
  3. re-secure the quick link to the round ring
  4. adjust the bungee so that the round ring rests in the armpit region.



inflator retainer setupThe SMS75 needed 2 Hollis SMS75 waistband d-ringsother minor mods.   I added 4 total D-rings to the waist band (2 on each side).  I find that the trim of the tanks is much better (for me) using these as lower attachment points for the tanks; I can also shift the tanks to lower D-rings as they become more buoyant due to air consumption.  The last modification for the SMS75 was to add a small bungee loop to the chest strap for inflator/deflator retention.

sidemount top attachment straps

A modification I make to all my sidemount setups is with large clips attached to bungees to secure the upper portion of the tanks.  I piece of bungee is looped through a clip and secured (using hog nose pliers/staples) to prevent slippage.  The tails are tied with an overhand knot to close the bungee creating a loop.  This will then get wrapped around the tank valve 3 times.  Finally it clips into the round rings on the side of the SMS75.  This makes the in-water trim absolutely perfect.

Parts List:

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