If you live in the United States and are looking to purchase a smartwatch with the latest in health monitoring technology, you may want to pass on the Apple Watch Series 9 and Ultra 2.

Apple has removed the blood oxygen monitoring feature from both devices due to ongoing litigation issues with rival Masimo. Worse, the upcoming Apple Watch Series 10 and Ultra 3 could also be affected by the dispute.

Fortunately, Apple is not the only brand to include this important wellness monitoring technology in its wrist wearables; Fitbit, Casio, Garmin, Polar, Samsung, and even Amazfit offer smartwatches with built-in pulse oximeters (SpO2) built-in smartwatches.

As someone who writes about fitness technology and wearables for a living, these are the five blood oxygen monitoring smartwatches I would buy right now instead of the Apple Watch Series 9 or Ultra 2.

The importance of monitoring blood oxygen saturation levels using a SpO2 sensor became apparent during the global COVID-19 pandemic.

When the lungs are unable to supply the body with sufficient oxygen, there is a risk of damage to other organs, which is obviously something no one wants. A sudden drop in blood oxygen levels can also indicate other serious medical conditions or episodes. Pulse oximeters are very useful because they are noninvasive and easy to use.

The first alternative to the Apple Watch is the Samsung Galaxy Watch 6. In terms of functionality and features, Samsung's latest smartwatch is closest to the Series 9 and Ultra 2.

Of course, it is best paired with a Samsung Galaxy device, or at least an Android smartphone. That said, Google Play's watch app store rivals Apple's in terms of selection, including a huge variety of free apps.

On the health front, the Galaxy Watch 6 offers skin temperature, ECG, heart rate, and SpO2 monitoring, although it lacks FDA approval in the US for its blood pressure monitoring technology. It is also a capable workout, sleep, and menstrual tracking device.

As of 2024, few wrist wearables will be able to match the smarts and health monitoring capabilities of Samsung's or Apple's latest smartwatches; the Google Pixel Watch 2 comes close. However, SpO2 monitoring is not in situ; it is measured passively while the user sleeps.

The next alternative to the Apple Watch 9 and Ultra 2 is the Fitbit Sense 2. This premium smartwatch from Google, or Fitbit, is one of the best fitness tracking smartwatches on the market today.

It tends to sell for $100 less than the Apple Watch 9 and comes in a similar rectangular form factor with a bright, responsive touchscreen Fitbit also boasts better battery life.

Health monitoring technology is essentially identical between the Sense 2 and Apple's latest generation of smartwatches.

Both models record physical activity, monitor stress levels and sleep quality, measure heart rate, track heart rhythm, and check skin temperature. Of course, only Fitbit offers SpO2 measurement.

Smart features are much less common on the Sense 2: aside from Google Maps, Google Wallet, and Alexa Voice control, there are no third-party apps.

Nevertheless, the Sense 2 does support wrist calling and texting. But if you want to browse Facebook or load Spotify from your wrist, there are smarter options, like the Galaxy Watch 6 mentioned above.

The Garmin Venu 3 is another top-class smartwatch with a built-in SpO2 sensor. Not only does it have excellent wellness monitoring technology, but it also has great workout, training, and recovery metrics.

Like the Fitbit Sense 2 and the latest Apple Watch models, the Venu 3 has a bright, vibrant AMOLED touchscreen. It also outperforms Apple in battery life and has a longer charging interval.

The Venu 3 is a great choice for hardcore athletes who want to gain serious insight into their performance and progress. However, it also offers a variety of useful features for the average athlete, such as built-in virtual sleep coach and nap tracking.

Like Fitbit, smart features are somewhat scarce. However, the pre-installed features are really useful. You can take calls from your wrist, and there is voice support for Siri and Google Assistant.

Additionally, the watch supports mobile payments and can store music offline, so you can leave your phone at home.The Garmin Connect IQ store is not up to par in terms of apps, but it is much more than what Fitbit offers (or Polar below). There are more options.

Like Garmin, the Polar Vantage V3 is a fitness-focused, high-tech watch with plenty of workout and wellness features. It also boasts a rich, crisp AMOLED touchscreen, excellent battery life, and a plethora of physical buttons around the bezel.

The Vantage V3 can monitor heart rate, ECG, SpO2, and skin temperature. It can also monitor sleep quality, workout recovery, and daily movement.

With over 150 profiles for physical activity, from snowboarding to disc golf, you don't have to be an Olympian to understand the V3's detailed post-workout maps, metrics, and insights. Dual-band GPS and altimeter provide extremely accurate position and elevation data. In addition, offline maps add versatility.

However, there are no advanced smartwatch features other than wrist music control and phone notifications.

The Casio G-Shock Move DW-H5600 may not look like a serious smart device. But rest assured, this model, modeled after Casio's legendary "dumb" watch DW5600 that debuted in the 1980s, boasts an arsenal of wellness technology, including an SpO2 sensor.

There is no touchscreen, only a monochrome LCD panel, and no third-party apps. However, Casio has partnered with Polar on fitness and health. As such, the G-Shock Move can track workouts.

It also monitors heart rate, sleep quality, workout recovery, stress levels, and of course blood oxygen saturation; it has better battery life than the Apple Watch 9 and Ultra 2, and is waterproof.

Sure, this may not scratch your smartwatch itch, but if it's legitimate fitness features you're looking for, the G-Shock Move DW-H5600 is one of the best-looking smartwatches on the market today.

The Amazfit Bip 5 and Withings ScanWatch 2 are also great choices if SpO2 measurement is your goal. It is also possible that devices with SpO2 technology on the Apple Watch Series 9 and Ultra 2 are available from third-party retailers, but that opportunity is rapidly disappearing.

Ultimately, no one knows when and how Apple and Masimo will resolve their differences regarding ownership of the blood saturation technology in question. Recent developments, however, do not paint a rosy picture of a showdown.

That is, the feature is unlikely to return to existing Apple watches or be included on new Apple watches. Get another brand of smartwatch instead.