On Sunday I tried out the DiveRite Optima. I’ve seen them in action before and was excited about my first bubbleless dive.

I skipped down the gravel hill towards the DiveRite Demo Days tent first thing in the morning. Another gentleman was already signed up, so we sat through the briefing together and I twiddled my thumbs waiting for my turn.

Pete explained the unit as well as our responsibilities for the dive, how to bail out, and what to look for on the dive computers: a constant PO2 automatically set to 0.7. We’d lie down on the swim platform first, then take a swim around. Pete would be very close by on our first silent dives. Coooool.

Gearing up, I slipped my head under the loop and we strapped things down to size. Pete had done all the predive tests so all I had to do was clip, clip, and go. The only odd thing I perceived was something rising and falling over my left counterlung as I inhaled and exhaled. I shrank away from it to see what was moving so close to me: just the BC inflator with an integrated Air-2 style bailout. No worries.

I assumed the computers would be wrist-mounted and left my bottom timers behind to clear up real estate on my midget forearms, but we then clipped both computers to the chest area for the purpose of this demo dive. It felt like a console system, which I suddenly recalled that I don’t like! You can change your set-point underwater too, which Pete did for me, switching from 0.7 to 0.4 for the ascent. Having an LED in front of your right eye isn’t as obtrusive as I initially suspected; your brain automatically focuses on whatever else you're looking at. Though I never had the DIVA (Display Integrated Vibrating Alarm) buzz the mouthpiece, I thought it could be useful in case the user gets really distracted.

I was pushing to exhale, and pulling to inhale. So this must be that “work of breathing” that I’ve read about! (Pete did mention these counterlungs are sized for the “average” diver whereas I turned out a tad runty.) Not that I have any experience to measure against, but it wasn’t so hard that I felt like I’d pass out from CO2 buildup, so we went with it. With the automatic set-point, my only real duty was to watch those numbers and focus on buoyancy. I knew we’d be cruising over the baby bass this time of year, and was determined not to smush their habitat.

Once we had our fins and masks on I tried to kneel on the swim platform, to no avail. Vivid memories of my open-water students saying “I need more weight!” flashed through my mind. I exhaled through my mouth – oh right, that won’t work… So I kept exhaling through the nose and came to about eye-level. 6 pounds were added to the top of the unit but I still felt light, and had to pull myself below the swim platform. It was bizarre not being able to sink by sighing.

I was surprised by how compact the unit felt. The over-the-shoulder counterlungs seem like they’ll crowd your head at the surface, but on the contrary, they’re not in the way at all once you’re horizontal and in the water.

Now that I was 6’ deep it was spookily quiet save the mushroom valves, the soft clicks a comforting reminder that yes, you are still breathing. Within the first ten seconds I noticed the difference; the bass under the platform stayed put, unfussed, instead of shying away from my bubbles! With Pete within an arm’s reach I checked both computers twice, stared at the little LED for several cycles, took my hand off the platform, and ventured out along the wall. Oddly enough, in the Optima the little bailout bottle felt much more noticeable than the 40 that I usually sling, and as soon as I started swimming my body tipped about 45 degrees (gasp!) before I corrected myself. The neat thing was that my gasp didn’t affect my position in the water column! Just for kicks I kept doing it. Gasp! No change. Gasp! Gasp! Still no change! Giggle. Pete gave me the “OK?” and I pumped my fists with excitement.

Swimming along the wall, I tried to dial in. I inhaled, inhaled, inhaled – SHIT – oh, inflate!! and saw Pete smiling out of the corner of my eye, as well as the comforting green light. I usually like to swim a few inches above the bottom, but upped that clearance to 3’ in anticipation of corrections and overcorrections.

The solenoid fired and startled me; it’s so loud in the spooky silence. I rolled from side to side to how much my cheeks would puff from one side to the other, and played around, exhaling through my nose to see if my cheeks would be less chipmunky. Nice. PO2s were still 0.69. Nice!! We swam along as my bottom timer was getting a tan topside, so I held the primary computer out to watch my depth.

I usually peek and peer to find the baby bass hiding in their round nests, but sans bulles, they swam in plain view over the sunlit algae. All of a sudden they ducked and hid, and I heard the reason becoming louder as I swam towards what sounded like a tornado: three open-circuit divers! Wow, is that what I sound like? Upon recognizing them, wicked thoughts crossed my mind. “They can’t hear me, so I could really mess with them…” but, the little angel on my shoulder (or was that only the BC inflator rising and falling?) said no, be nice.

Pete wrote on his slate “Trim looks good” (Sweet!) and “Swim to platform?” I felt a little anxious about leaving the sunny gravel wall, and empathized again with my Open Water students. I had to make some adjustments to dial in: chipmunk cheek, exhale through nose, plummet, inflate, ascend, dear god, exhale through nose, inflate, discombobulate, readjust… and off we go at last! Once we got there I noticed that the entire set of platforms was sinking. Vent vent. Sigh. Vent. Exhale. Both my BC and drysuit were empty; in fact, I dove with a lot more squeeze than I’d normally tolerate because I thought one puff might tip the balance, and I’d be up and away. I whipped out my Wetnotes to convey my frustration and futzed to open them while clinging onto the beam. On Pete’s slate I finally wrote “Fighting to keep down” to which he responded “Exhale through nose.” Again? OK… And sure enough, I sorted myself out at last, still kicking a bit to stay down, but with far less aggravation. Ahhhh. Pete adjusted the set-point to 0.4 (pretty smart how you can switch it so easily) and we headed back to the wall.

The dive was over far too soon. Our time was up, and there were others also twiddling their thumbs topside to test drive the Optima. I’m still giddy about it, and am now contemplating how to eat and drink on a rebreather.