Before revision: Tool bags are used by technical divers for similar applications to pockets, and professional divers use then to carry small sets of relatively light tools and components in clip-on bags, and heavier tools and components in independent bags which are set down when not being used for the carrying function.
After revision: Tool bags are used by technical divers for similar purposes to pockets, and professional divers use them to carry small sets of relatively light tools and components in clip-on bags, and heavier tools and components in independent bags which are set down when not being used for the carrying function.