Das Boot is a gadgeteer whose heavy diving suit has been heavily modified. It's been ruggedized, of course, and it boasts some strength augmentation to help with the weight. It mounts an array of powerful optics and microphones. But most notable is the electrogalvanic generators that generate a field which allows him to turn invisible and even phase through solid objects.
His primary weapon is a low-velocity rocket launcher whose rockets are equipped with their own invisibility fields. But he has also been known to use a harpoon, or even a large monkey wrench, if circumstances dictate.