Does anyone here have experience with underwater drones? I don't mean flying drones that can also submerge a short time. I just mean the strictly underwater tethered type. I've been asked to research them for conducting a submerged aquatic vegetation survey by my firm -- with me as the operator. A preliminary search shows they generally run about $2K, but we'll need a good one so any recommendations based on experience would be appreciated. Torpedos optional.