Mark One's Pryme Vessyl is an iPhone-connected cup that's designed to track your daily liquid intake, making sure you're at your optimal hydration level. According to Mark One, hitting an ideal hydration level can increase your energy level and improve your mental balance.

Paired with an accompanying app, Pryme Vessyl calculates a user's hydration needs based on height, weight, activity level, and other factors, making sure that intake level is met by measuring each sip of water or liquid through accelerometers in the cup itself. Hydration needs change from day to day, so the goal of the Pryme Vessyl is to make sure users are getting enough hydration as activity level shifts.

prymevessylmain
The idea is to drink all of your liquids -- coffee, tea, water, juice -- out of the Pryme Vessyl to get an overall picture of liquid intake and track any deficits.

Design

Mark One's Pryme Vessyl features a clean design that looks like it could have come out of the Apple design lab. It has a sleek white exterior that's soft and smooth to the touch with a glass interior. There's plastic at the top of the cup and the lid, which fits into the top, is also plastic, so it's not going to be a good purchase for those who prefer to avoid plastic drinking vessels entirely.

The lid of the Pryme Vessyl is problematic because it can be difficult to remove. Pressing with a thumb on the lid slides it over to reveal an opening to drink from, and pulling up on the extra plastic pries open the lid. It takes a lot of force to open the lid of the Pryme Vessyl, but Mark One says it will loosen up over time.

prymevessylinside
Once I learned the trick for opening the lid, I found it simple to do, but it does require pulling so hard in an upward motion that it feels I'm going to break something. Popping the lid off needs to be done every time the cup is filled, and because it only holds 16 ounces, it needs to be filled frequently if you drink a lot of water.

Drinking from the Pryme Vessyl is like drinking from any travel cup with a lid. The opening is small so you can't get much liquid per sip, and it can be awkward to drink from because the top part doesn't fully come off. The lid opening is not large enough to fit a straw, and for the first several days of use, I noticed a plasticky taste.

prymevessyllid
With the lid snapped into place, the Pryme Vessyl looks like it should be watertight, but it's not. If you put it in a backpack or bag and it tips, it's going to leak. Because it's lined with glass, the Pryme Vessyl is heavier than your average travel cup, but it does support both hot and cold liquids and it can be used with or without the lid in place. There's no real insulation aside from the glass, so it's not going to keep cold drinks cold or hot drinks hot and it will feel warm or cold based on what's inside it.

prymevessylfinal

This line is where the LED is located

An LED on the side of the cup can be pressed to display a line representing how close you are to reaching your daily water intake goal, and it also lights up when charging the battery. I found myself wishing the LED indicator did more, like letting me know when the cup disconnected from Bluetooth or how much water was left.

Functionality

There's an accelerometer built into the Pryme Vessyl, which is what tracks the water level in the cup and detects whenever a sip is taken so it can be recorded. Built-in Bluetooth transmits that data to the iPhone, keeping tabs on all of the liquid consumed through the cup. It tracks as little as 0.5 ounces at a time, which is a relatively small sip.

Every couple of days, the Pryme Vessyl inexplicably disconnected from my iPhone even though it said Bluetooth was still enabled, and I had to go through an entire reset process to fix the connection. When it isn't able to connect to the iPhone, the cup will store sips and upload them later, so it doesn't need to be used alongside the iPhone at all times and data isn't lost if a connection is lost.

prymevessylsideview
When walking around with the Pryme Vessyl, transporting it in the car, or washing it, I had errant sips added to my liquid intake totals. Mark One says an update is in the works to fix this problem and improve the algorithm that detects when a sip is taken, but it accounted for several inaccuracies.

Phantom sips can be deleted by pressing and holding on the drink in the timeline screen, which is how any liquid can be deleted. This isn't exactly intuitive -- the Vessyl needs an app design that makes hidden features like this more apparent. The Vessyl can also be turned off when washing or traveling, another feature that's not obvious because it's done through a teeny tiny hole in the bottom of the cup.

With an accelerometer, Bluetooth, and other electronics inside, the Pryme Vessyl needs to be hand washed -- it's not dishwasher safe. It's also not microwave safe and Mark One says it shouldn't be placed in the freezer, but it can go in the refrigerator for short periods of time.

prymevessylcharger
The Pryme Vessyl needs to charge every day to two days, and charging is done inductively through a metal base on the cup that attaches to an included coaster. It's definitely not convenient to have to charge a cup, but I put the coaster on the table where I work, which made the charging process relatively painless. It generally took just under two hours to fully charge the cup.

App

Like most smart objects, the Pryme Vessyl interfaces with the iPhone using an app (there's also an Apple Watch add-on). Available for free in the App Store, the Pryme Vessyl app is used to track how much liquid is consumed during the day. Using input including height, weight, age, and activity level, the app calculates an ideal hydration level for you.

Based on activity information pulled in from Apple Health, Jawbone, and/or Fitbit, it adjusts hydration calculations on an ongoing basis. Sleep schedules are also input so it knows when to track liquid intake, and it should be noted that when the app thinks you're sleeping, it will not track sips at all. Mark One says this is because nighttime water intake disrupts sleep, but this is inconvenient for people who would like to track overall liquid intake 24 hours a day.

Each sip of water from the Pryme Vessyl is tracked in the app and fills up a circle that takes up most of the main view. The circle represents hydration level and the idea is to drink enough liquid to stay at your "Pryme" for the entirety of the time you're awake.

prymemainview
Scrolling downwards displays a timeline of the exact number of ounces consumed at each point during the day (as tracked by the cup), but the main circle view of the app doesn't give a picture of overall ounces. All it does is let you know whether or not you're at your Pryme, aka optimal hydration level. In landscape mode, the timeline is displayed as a line graph.

Tracking from the Pryme Vessyl is automatic, but drinks not consumed through the cup can be entered manually. When entering a drink manually, the app offers up three preset ounce options, but there's a hidden option to customize the amount consumed at the time it was consumed at. A similar option exists for entering activity.

prymeadddrink
The app, while pretty, is overly simple and surprisingly unintuitive, mainly because there are no instructions to let you know how to manage the features. There's no obvious way to see the total ounces consumed, but hidden in a weekly overview menu (which doesn't make it obvious you should tap), there's a way to see full water consumption for the day.

prymedailyoverview
One of the biggest shortcomings in the app is its inability to store more than a week's worth of water consumption data. Because it links to the Apple Health app, which supports the tracking of liquid, there's a way to get data for longer periods of time, but the app itself only displays one week of information. When tracking hydration to improve health, most people likely want historical data readily available.

The Pryme Vessyl app is designed to deliver notifications, but in my experience, these were inconsistent and not useful. I reliably got one notification each morning, but notifications during the rest of the day were sporadic. On one day when I fully met my Pryme goals for most of the day, I received five notifications reminding me to stay at my Pryme or take another sip of water, and on another day where I drank next to nothing from the cup, I received no notifications.

I expected a smarter app to go with a smart cup, perhaps letting me know the times of the day when I needed more hydration based on historical activity information or data on how my personal hydration needs were being calculated on a day to day basis, but it didn't do much more than wishing me a good morning or occasionally telling me to take another sip.

On the plus side, the app used very little battery life on my iPhone despite being connected to the Pryme Vessyl and transmitting data over Bluetooth all day long.

Bottom Line

Using the Pryme Vessyl to its full potential is a compromise because you have to hassle with drinking liquids exclusively through the cup, fuss with connectivity problems, and charge yet another device. Liquid consumption tracking is accurate most of the time, but you're going to have to deal with inaccuracies from time to time, which require time and attention to watch for and fix.

Over the time that I tested the Pryme Vessyl, I found it surprisingly inconvenient to pour all of the liquid I drank, from regular water to tea to cans of sparkling water, into the cup. I had the option to add liquid manually when I didn't feel like drinking out of the Pryme Vessyl, but when I got into the habit of doing that, I wondered why I wasn't using a simple water tracking app that does away with the need to drink from a single cup.

prymevessylmain2
Even on days when I was active, my water needs didn't shift a lot and I didn't notice the cup telling me to drink much more than I did on an average day, so the Vessyl didn't do enough for me to justify its cost. Since I already drink a lot of liquids during the day, I didn't notice any measurable difference consuming water from the Vessyl and staying at my "Pryme."

If you're someone, like me, who already drinks a lot of water, tea, juice, and other liquid throughout the day, you don't need the Pryme Vessyl. If you're someone who has a hard time remembering to drink enough water in a day, whether because of a busy schedule, a preference for soda, or another reason, I guess the Pryme Vessyl has the potential to be a decent investment.

A person who is regularly dehydrated and adopts the Pryme Vessyl will undoubtedly notice the health benefits that come with drinking more water throughout the day, and if you're paying $99 for a cup, I bet you're going to use it.

It's worth noting that water intake can be tracked much more cheaply and smartly through a simple water tracking app available from the App Store, which is a good starting point for anyone who wants to up their water intake. Liquid consumed will need to be entered manually, but there's no charging, no setup, no fussing with Bluetooth disconnects, and no need to drink out of just one vessel.

Pros:

  • Accurate liquid intake tracking in most conditions
  • Encourages more water consumption
  • Works with hot and cold liquids
  • Apple-style design
  • App uses little battery life

Cons:

  • It's another device that needs frequent charging (every two days)
  • Only holds 16 ounces
  • Not as easy to clean as a regular cup -- not dishwasher safe
  • Loses Bluetooth connection a lot and requires resetting
  • Doesn't store more than a week's worth of data
  • Inconsistent notifications
  • Not watertight, so it leaks

How to Buy

The Pryme Vessyl can be purchased from the Vessyl website for $99 and $10 shipping. It is also available from Apple.com and in Apple retail stores for $99.95.

Note: Mark One provided a Pryme Vessyl to MacRumors free of charge for the purposes of this review. No other compensation was received.

Top Rated Comments

tod Avatar
103 months ago
I already have an app that correlates my activity level with hydration and notifies me when I need more water. It's called thirst and it's a standard feature of humanity.
Score: 7 Votes (Like | Disagree)
Saturnine Avatar
103 months ago
A [bad] solution looking for a problem.
Score: 4 Votes (Like | Disagree)
C DM Avatar
103 months ago
@jclo: In your case I understand the need for reminders since you can't tie water to 4 meals reliably. The app I found sends notifications via the phone to remind you to drink, and you can use any glass: https://itunes.apple.com/us/app/daily-water-free-water-reminder/id466387763?mt=8

There are many other apps. Just Google "glasses water day app". ;) Here's another that even lets you track what type of liquids you've had (for people suffering from OCD?): https://itunes.apple.com/us/app/waterlogged-drink-more-water/id352199775?mt=8

The second app offers "smart reminders" that only sends reminders when you're lagging behind and haven't drank anything in too long. What a great feature!

There are countless free solutions for this non-issue.
Just as there are for reminders to move more and increase your step count, but again, actual step counter devices are more than popular with people owning them and buying them left and right.
Score: 3 Votes (Like | Disagree)
SteveJobzniak Avatar
103 months ago
I'm sure there are hardcore liquid enthusiasts out there who would appreciate this product.
Seeing a fellow human being write the phrase "hardcore liquid enthusiasts" with a straight face to excuse this useless product...



I hope the company is reading this: This is the dumbest thing I have ever seen humanity create, and everyone who ordered one is a fool.

We already know when we are thirsty. Nobody needs to carry around special "smart" water cups, replace its batteries, and use fiddly tracking-apps just to get water into their belly.

Just read how much you need to drink in one day, and drink that much.

Drinking is one of the easiest things you can ever do in life. You've survived this long just fine. If you need more, just drink a few more glasses.

Drinking more is free and compatible with any glass in the world.

Next app from this company: How to breathe. "Remember to breathe. Type in how many breaths you have had today."

The movie Idiocracy apparently wasn't a comedy. It was a prophecy...


At least they spelled vessel in a cool way (Vessyl).
Given the stupidity of the product, I wouldn't be surprised if the spelling mistake is an accident. ;-)
Score: 2 Votes (Like | Disagree)
8692574 Avatar
103 months ago
And I hope each and every one of you grows up one day and attempts to develop a product around an idea of your own and discover how much work it actually takes, get buried in it, struggle through, only to enjoy idiotic threads like this written about you.
Critics are what makes a product grow up, I am sure Mark One can stand the critics and know what to do with them without a "lawyer" advocating for them

That said people are entitled to their opinion, and there's nothing bad with negative comment as long as they are respecful, one thing is though to have setbacks and work hard to fix them wich is normal in any business, but the way they managed the situation is not good......and if you did not preorder and followed the history, you are just giving an uneducated opinion.

People who believed and spent their money to support the campaign deserved better, because it is with their money that Mark One was able to see "much work it actually takes, get buried in it, struggle through", without "investor" they would be still airing the "commercial"trying to invite people to join..

They had a great idea (they might still have..) they did a good marketing campaign but they failed to deliver (so far) promised an extra to who would stick with them wich is good but failed to deliver for many!!! and yet they advertize it as .....few more months and we are in.... while in reality they said that years ago..

Idiotic is someone who cannot accept critics .....and at least there i cannot say anything against Mark One, they never fought back (because they know they are in defect) they know their investor deserve better, they just don't know yet how to make it happen....
Score: 2 Votes (Like | Disagree)
jclo Avatar
103 months ago
When they first marketed this, the cup could detect what liquid type was added. The review marks no mention of this. Was this removed or just not tested?
That is a different cup, called the Vessyl. That cup isn't out yet -- this is a different version that just measures water intake. From what I understand, there are some delays with the Vessyl's production ramp up.

Customers who pre-ordered the original Vessyl have been given a free Pryme Vessyl.

Here's the original Vessyl article for those interested: https://www.macrumors.com/2014/06/12/vessyl-smart-cup/
Score: 2 Votes (Like | Disagree)

Popular Stories

iPhone 16 Camera Lozenge 2 Perspective Gray

Five Key Upgrades Coming to iPhone 16

Friday March 15, 2024 1:45 pm PDT by
The iPhone is Apple's top-selling product, and it gets an update every year. In 2024, we're expecting the iPhone 16 and iPhone 16 Pro lineup, with an arguably more interesting feature set than we got with the iPhone 15 and iPhone 15 Pro. Subscribe to the MacRumors YouTube channel for more videos. Capture Button All four iPhone 16 models are set to get a whole new button, which will be...
When To Expect New iPads Feature 1

Apple to Announce New iPads on March 26, Rumors Claim

Monday March 18, 2024 4:02 am PDT by
Apple is widely expected to release new iPad Air and OLED iPad Pro models in the next few weeks. According to new rumors coming out of Asia, the company will announce its new iPads on Tuesday, March 26. Chinese leaker Instant Digital on Weibo this morning 日发布%23">claimed that the date will see some sort of announcement from Apple related to new iPads, but stopped short of calling it an...
airpods 3 orange

Two New AirPods 4 Models Expected to Launch in September or October

Sunday March 17, 2024 7:56 am PDT by
Apple suppliers will begin production of two new fourth-generation AirPods models in May, according to Bloomberg's Mark Gurman. Based on this production timeframe, he expects the headphones to be released in September or October. Gurman expects both fourth-generation AirPods models to feature a new design with better fit, improved sound quality, and an updated charging case with a USB-C...
iphone se 4 modified flag edges

iPhone SE 4 Expected to Depreciate Heavily

Tuesday March 12, 2024 9:04 am PDT by
Resale value trends suggest the iPhone SE 4 may not hold its value as well as Apple's flagship models, according to SellCell. According to the report, Apple's iPhone SE models have historically depreciated much more rapidly than the company's more premium offerings. The third-generation iPhone SE, which launched in March 2022, experienced a significant drop in resale value, losing 42.6%...
iOS 17 Passkey With Apple ACCOUNT Feature

'Apple ID' Expected to Change to 'Apple Account' Starting With iOS 18

Sunday March 17, 2024 7:13 am PDT by
MacRumors was first to report that Apple was planning to rebrand "Apple ID" to "Apple Account" across its software platforms and websites like iCloud.com as early as this year, and now Bloomberg's Mark Gurman has corroborated this change. A mockup of the new Apple Account branding In his Power On newsletter today, Gurman said the new "Apple Account" branding will start to be used later this...
General iOS 17 Feature Orange Purple

iOS 17.4.1 Update for iPhone is Imminent

Monday March 18, 2024 5:27 am PDT by
iOS 17.4.1 and iPadOS 17.4.1 should be released within the next few days, with a build number of 21E235, according to a source with a proven track record. MacRumors previously reported that Apple was internally testing iOS 17.4.1. As a minor update for the iPhone, it will likely address software bugs and/or security vulnerabilities. It is unclear if the update will include any other changes. ...