I use this: https://www.amazon.com/Piscifun-Backpack-Capacity-Waterproof-Protective/dp/B07CGJDTNG/ref=mp_s_a_1_4?crid=3N3NO4E3AOB7J&keywords=piscifun%2Bbackpack&qid=1659130988&sprefix=piscifun%2Bba%2Caps%2C83&sr=8-4&th=1&psc=1

The trays are trash sonid replace them, and I only keep 3 to keep the weight down. Works great, comfortable, plenty of attachment points etc.

Edit: pretty sure it just has a raincover and it is not waterproof.