GY-MS5803-14BA Pressure Sensor Breakout High Precision Fluid Liquid Gas Altitude Module I2C SPI Interface for Arduino

This is the second sensor I purchased for measuring pressure under water. The first stopped working minutes after immersion in a few centimeters of water. So I purchased a second one. This time I coated the PCB with an acrylic coating to protect the electronics from water. Unfortunately, this didn't help. I immersed the sensor in 8 cm of water, and after a few minutes the sensor stopped working completely and permanently. The detector is simply not waterproof at all. If you plan to get this sensor wet, you will be out the $40 in no time.

I've used this little sensor to measure air and water pressure. It works great! For water pressure, you need to isolate all but the membrane of the sensor from the water and keep the electronics package totally dry. It's not enough to paint the PCB with a waterproof coating. You need to put some kind of collar on the sensor and enclose the rest in a watertight container.