Real-time Underwater Toolkit for Blender! This tool enables you to create underwater scenes quickly and efficiently, with real-time rendering using the EEVEE engine. Say goodbye to the lengthy process and high hardware demands of traditional methods—this toolkit is optimized for all computer configurations.

If you love this tool, I have some fish and marine animal models that you can drop into this underwater scene:

DOLPHINS & WHALES 3D MODEL COLLECTION

ALIEN FISH 3D MODEL