Meet the Nu Grip: a 4-in-1 grip and tripod that floats in water to let you capture hands-free underwater shots. It has 3 independent legs to bring stability while floating. You can use it with your iPhone, GoPro camera, and other comparable devices. The Nu Grip weighs only 140g and can be used as an extended pole with a simple twist and pull mechanism.
This underwater tripod is compatible with the ProShot waterproof iPhone case. It has an attachment point for a lanyard for a secure grip. The Nu Grip has an ABS and aluminum construction. You can find out more about it here.