Water temperature - how long will it take for correct temperature

[kohjl]

@Gosem Just did a test by dunking my watch into slightly chilled water. Here’s what I got:

It took 40 seconds for the sensor to get from about 29°C to 26°C, and nearly another minute to get from that to the final reading of 25°C. But as you can see from the graph, despite the 25°C reading, it was still equalising the temperature towards the very end of the test.

The test setup:
All sensors are allowed to rest in a shaded and well-ventilated area to be allowed to acclimate to room temperature. The sensors comprise a Suunto Ocean, an Aranet 4, and a Thermapen IR (temperature probe only).

Their initial readings just prior start of the test were:

• Suunto Ocean: 29°C
• Aranet 4: 29.2±0.3°C
• Thermapen IR: 29.0±0.4°C

These represent the ambient air temperature. For what it’s worth, the Thermapen IR comes with a calibration certificate dated June 2020 that is traceable to a laboratory-standard thermometer.

I then initiated a custom sport mode for recording temperature and left my watch in slightly chilled water. The initial temperature of the water according to the Thermapen IR was 24.6±0.4°C.

The test ended when I came back from my shower and saw that the watch and the Thermapen IR gave (apparently) the same reading of 25°C.

Hope that helps.

[Gosem]

@kohjl hey , thank you so much for your time and effort, that’s amazing
Unfortunately the result is not what I wanted to hear … I thought they changed the sensor.

But thank you so much ️🥳

[kohjl]

@Gosem I’m even more disappointed they didn’t upgrade the HR sensor like they did for the Race S, despite the back-to-back launch with both watches

The hardware is there, but the will is not.

[Gosem]

@kohjl … that’s a pity as well … I don’t understand either. I guess that is because of the special diving certification, which needs a lot of time.

[raceaddict]

@Gosem I think so, the ocean watch code is DW223, Vertical was OW222, Race was OW224 and Race S is OW233 (and 9PP was OW211).
So, I think the Ocean project started in 2022 as Vertical and Race, and the Race S OHR wasn’t ready yet.

[Gosem]

@kohjl hi, another idea came to my mind … if you set the watch on diving sport mode, perhaps it will react faster?
If you have time and fun … perhaps you could please try that ️

[Shane Watson]

@Gosem said in Water temperature - how long will it take for correct temperature:

Hi,
I was wondering how the Ocean is measuring the water temperature?
Is it similar to the Apple Watch Ultra with a second temperature sensor in the display? This would be much faster then with the normal sensor.
I am asking because if jump into a cold river or lake will it immediately show and log the correct temperature?
Would be grate and a reason to change from the fenix to the ocean … for me
Many thanks for answering my question.

Hi, great question! The Ocean measures water temperature using a highly responsive external sensor designed for aquatic environments. While it’s not identical to the Apple Watch Ultra’s dual-sensor setup, it provides accurate and near-instant readings. Perfect for logging temperature changes during activities like river swims. Hope that helps your decision!