I buy everything I review. To receive FIVE stars, a product must meet >90% of the manufacturer’s claims. I don’t subtract because I don’ t like the color or appearance (too subjective and personal). I review form, function, ease of use, and construction quality. Please forgive typos: I’m an evidence-based scientist, NOT a typist. If you find my review helpful, please click “YES”. This helps me improve future evaluations (which I do for free to help people make more informed decisions).
Their Claim: Dive computer that meets the most demanding diver’s needs
My Verdict (details below): True (with some missing features)
I figured Mares makes great SCUBA products (everything I own is Mares), and this computer has great reviews, so why not go for it? I’m glad I gave it a try (but had to return it, see below).
First, I immediately went to divecomputertraining dot com and took the online course. It’s a MUST for just $5. It is an amazingly simple course to follow and taught me everything I needed over about two hours to use this computer with confidence. I can’t imagine learning how to use the PRO without it. They have a lot of other computers on that site that you can learn as well, so have a look. When you pass the final test (yes, there are tests you must pass to continue to the next module), you can pay $5 for a certificate. Kind of cheesy, but I did it and keep it in my SCUBA file.
When you push the single red button, it turns it on (it goes dark after about a minute to save batteries, except when in the water where it’s always ON), and you see the time, with dive time and depth displaying “---“ because you’re in PRE-dive mode. If you recently completed a dive, it displays Surface Interval (SI). It also tells you whether you’re in AIR, BOTTOM TIME, or EAN dive mode. Very simple to understand, and the #’s are HUGE, so that even without my reading glasses, I can easily see them. That’s a big bonus.
Once you’re ~4 feet under, it turns on the bottom timer and goes into DIVE mode. Once there, you can’t change any settings, so if you push the button, nothing happens other than turning on the backlight. It is very accurate with regard to depth. It was +/- 1 foot of the Oceanic computer mounted in my rental dive console. The features are all described on the Mares website and in the very thorough manual, so I won’t go into them all here.
Set-up is very easy. Just push the single red button until you get to the mode you want, and then HOLD the button and it enters that mode for adjustments. It has MODE (DIVE and TIME), SET, LOG, PLANNER, PC, & INFO areas.
MODE:TIME is for setting time of day, date, etc., that the PRO uses to time stamp your dives.
MODE: DIVE is where you select between AIR, EAN, and BOTTOM TIME as your dive mode. EAN has a bunch of settings for those of you who are certified for Nitrox dives. I’m not. You can also set it for the least conservative algorithm to most (P0 – P2, respectively) to calculate your allowable bottom time. I use P1 for an added margin of safety. To get the longest bottom times, use P0. You can also set altitude, which adjusts the dive algorithm to take that into account. There are four presets: 0’, 2300’, 4900’, and 7900’. Finally, you choose SALT or FRESH water, which is important for a number of calculations.
LOG is where you find your dive records. I think it holds about 35 hours of diving in its memory with 5-second samplings. You scroll through the dives, and then HOLD the button to enter that dive log for more information. You’ll find your dive date, Fi02, depth, temp, BT, etc., all quite easily accessible. (My unit was defective in that it kept reporting I was using two gasses, 24% and 32% 02, which wasn’t true. I sent it in and they replaced it under warranty.) Then scroll to the next. Every five dives, it puts a BACK screen, so you can go back to your most recent dive instead of scrolling to a dive you may have done four year ago, and THEN coming back to your most recent dive. That’s a very nice feature. Dives are numbered 1 through XXX, with 1 being the one you just did. If you have 15 dives, log 1 is the most recent, 15 is the oldest.
PLANNER is awesome. Go there, and based upon your last dive, SI, desaturation time, etc., it tells you, once you scroll to the depth you intend to dive (40 – 139 feet), how long you can remain at that depth for a no-deco dive. Keep in mind, however, that the # assumes you spend the ENTIRE dive at, say, 50 feet. Of course, you’re not going to do that, and the PRO keeps track of your AVERAGE depth, and the algorithm adjusts the no-deco time accordingly. More time at shallow depth means the dive can last longer and remain in the NDL range.
ALARMS are for rapid ascent (30 feet/minute), exceeding a safe pp02 for EAN dives, CNS=100% 02 toxicity, a missed decompression stop, and low battery during a dive. I wish they also had a depth alarm (see below) as well.
PC is for when you’re hooking it up to the USB cable (which is not included, and costs about $80 online). Unlike the Puck (which also has a cable for downloading your dive log) but cannot upgrade firmware (a real negative about the Puck), the Puck PRO has firmware upgrade capability through this USB cable (which clamps onto the computer at the 3:00 position, which means as Mares makes changes and adds new features (maybe they’ll read my suggestions and add them???), you have access to them. On the downside, currently you cannot upgrade firmware upgrades on a Mac, only a PC. But the dive log software is available FREE for both computer systems on their website. The Dive Diary works well on my Mac and allows me to get all kinds of data, once I upload the dives, about a particular dive by dragging a slider bar to any portion of the dive and it tells me my depth, bottom time, temp, etc. It’s pretty neat to use. You can add notes about your dive in a special box.
INFO is where you check the battery strength (which you need to do before every dive vacation to be sure it’s okay), firmware version installed, and unit serial #.
Once you surface, if you stay there for 3 minutes without going back down, it enters the POST-dive mode. The first screen shows your surface interval (SI) since your dive ended, which starts at 0:00 and counts up to 24:00. After that, you are totally desaturated and it displays “---“. It also has TIME TO FLY, which tells you when you’re safe to travel by air in a commercial airliner at 30,000 feet. Generally, it starts at 12 hours for a single dive, and 24 hours for multi-dive days.
Underwater, the large face is very easy to read, and has a backlight if you push the red button. During ascent, it displays the rate in feet/minute and has a bar graph display as well. If you exceed 30 ft./min (or 40 if you go beyond a certain depth), it beeps to warn you and you have to slow down. That’s a nice feature. It also tells you if you need to make a DEEP STOP during ascent, generally for 1 minute. You can have multiple deep stops on a single dive. The deeper you go, the more stops you’ll be advised to make. I don’t exceed 50 feet, so I’ve never had a deep stop warning. Miss it, and it beeps at you (it’s angry you didn’t listen). However, if it wants you to make a DEEP STOP (which are mandatory), once at that recommended depth, two arrows facing each other appear so as to indicate you’re spot on and should stop your ascent. If you go above that depth, the countdown timer stops, and you have to go back down to the recommended DEEP STOP depth displayed to start it again. It is constantly recalculating the DEEP STOPS and NO-DECO time limits (updated constantly and adjusted accordingly). For the 15 foot SAFETY STOP, which it recommends for every dive over 33 feet of depth (2 ATA), it starts a 3-minute timer between 10 and 18 feet. Go above that, and the timer stops but it doesn’t beep because it’s not angry. You have to go back down in that case and it starts over. After the 3:00 counts down to 0:00, it’s time to continue to the surface. (If you have an ascent line to hold you in place, it’s much easier than trying to hover with buoyancy control at 15 feet.)
It has a BOTTOM TIME mode, which records your bottom time, depth, ascent speed, and temperature. No deco limits, beeper warnings, DEEP stops, etc. You can’t select BOTTOM TIME mode if you still have desaturation time left from a prior dive; the PRO won’t allow that.
If you go to the surface for LESS than three minutes, and go back down, it starts the bottom timer where it left off, PLUS the surface time. So, if you hit the surface after 22 minutes of bottom time, stay there for 2 minutes to snorkel to another site, and then go back down, it starts at 24” (22” + 2”) minutes, not 22”. The BT displays minutes only, not seconds. It also displays maximum and current depth, as well as temperature (C or F). That’s good for thermoclines.
It’s called the Puck PRO for a reason. It’s the size of a hockey puck, no joke. It’s HUGE. The wristband is very long to fit over a wetsuit. I cut mine down to size so it wouldn’t flop around. It’s a rubber band and should hold up forever if you care for it properly.
The battery is easy to replace, although you should use a new O-ring. However, Mares refuses to sell it to plain old commoners (you know, the guys who keep them in business?) like me. I had to find a retailer in the UK, and they sell them only in 10-unit bags. Cost about $15.
A shout-out to Rick in technical support. He is amazingly helpful and was a tremendous resource to me. Their phone support is tremendous.
I love this dive computer. It’s so simple to use, easy to read, has easy to understand features, is super easy to set up, and is very accurate. I felt very safe with it.
But of course, there are big misses with any computer, and the Puck Pro is certainly no exception (I beta test medical software and road bikes, so I am always looking for improvements).
1. No stopwatch. It should have one so you can time when you need to meet up (if the dive master says come back in 1:15 minutes, you should be able to set a stopwatch). If obviously has this capability because it’s a watch. It would work like this; A CHRONO would appear in the menus list, HOLD the button to enter, PRESS it to start, PRESS to stop, then HOLD to leave the chronograph mode and reset it 0:00. How hard can that be?
2. Bottom timer stops if you’re on the surface for 3 minutes. That’s bad. I like to surface, snorkel to my next reef or underwater feature to save air, then resubmerge. With the PRO, every time I go back down, that’s considered a new dive. When I was taught in the 80’s, that was how we dove. We could make a tank last four hours that way, and we generally did, because it was so expensive to dive back then. With the PRO, that could mean 10 or more dives on one single-80 cylinder. Good luck plotting each dive in your logbook. They should have a user-definable surface time before the dive is considered over. So, if you WANT three minutes, that’s great. I’d set mine for about 15”, and the bottom timer would restart where it left off when I hit the surface, and NOT add 13 minutes if that was how long I snorkeled for. This would be VERY easy to do.
3. Depth alarm. I have a medical device that can’t exceed 40 feet due to pressure considerations. There is no depth alarm to alert me that I’ve hit that depth. It’s so simple to add, yet they’ve chosen to omit this critical feature. There are plenty of reasons to have this besides medical devices. Another is that your current dive shouldn’t be deeper than your previous dive on a multi-dive day. Because of this feature being absent, I’m forced to return my PRO and am now looking for a computer that has it, such as the Oceanic Veo 3, which is less user-friendly and more expensive than the PRO, but I NEED that feature. With over 500,000 of these medical devices (neurostimulators) out there, Mares is missing the boat by a very wide margin by excluding this feature.
4. O-rings. Mares should sell them to consumers. They advertise “user-changeable batteries”, but that’s not true unless you have fresh O-rings, which dry out over time. After using a quarter to open the compartment, you pop in the new battery and put on a new O-ring with some silicone sealant (not a petroleum based sealant as that breaks down rubber) to keep it watertight. It doesn’t seem right that I have to spend about $25 to have a dive shop do it, or buy 10 O-rings from the UK (couldn’t find them in the US). I think I’m more than capable of changing a simple watch battery when the only tool required is a US quarter. It’s MY computer, and I want to be able to change the batteries when I want. Plus, if you’re away on a trip, guess what? You’re out of luck, because resorts don’t have O-rings for every computer. Dive ruined, trip over. Back to the RDP, which severely cuts short your dive time for reasons I won’t go into here.
I absolutely LOVE this computer, foibles and all. If it had a DEPTH ALARM, I’d keep it. But it doesn’t, so it’s going back to Amazon. That’s a lose-lose situation for Mares and me. And it’s a damned shame. Mares, if you’re reading this review, please let me know if you agree.
Slim design for a perfect fit;Large display for superior readability;Intuitive user interface