| Acou-stik | Manufacture of underwater communications devices |
| D & N Products | Manufacturer of signaling devices |
| Dive-Alert | Manufacture of surface and underwater signaling devices |
| Divelink | Manufacture of underwater communications devices |
| Ocean Reef | Manufacturer of full face maks communications+G118 |
| Scuba Bell | Manufacturer of underwater signaling devices |
| Trigger Scuba | Manufactures of communication systems |
| Wulich Wave | Manufacturer of underwater pager |