No. The Artemis Watch is splash resistant, not waterproof. It has no sealed housing and no IP water-resistance rating, so keep it out of rain, showers and swimming pools.
The reason is in the design. The case has exposed ports and headers so you can connect external sensors and code against the hardware, and those same openings are where water gets in.
In practice:
Fine: damp air, dew, the odd splash while you are washing your hands.
Not fine: heavy rain, showers, baths, swimming, washing up, or leaving it somewhere persistently humid.
If it has already got wet, that is worth acting on straight away. Take it off the charger, switch it off, dry the outside with a soft cloth, and leave it somewhere dry and warm — warm, not hot — for a day or two. Do not charge it or switch it on until it is completely dry.
If it will not start after that, message us here, or email [email protected], with your order number and a photo of the watch, and we will tell you what can be replaced and what it costs. Water damage counts as damage in use rather than a manufacturing fault, so the part is chargeable, but we always quote before we send anything. The detail is in Do your kits have a warranty?.