Subconn BH4F Thru-Hull Kit These low current thru-hull connectors comply with PSUBS Guidelines for communications.   Each vessel should have at least one Subconn BH4F installed. VHF + OTS Comms Schematic PSUBS approved schematic layout and wiring diagram of VHF and OTS communications equipment used in the R300 submersible owned by Cliff Redus.   All vessels should have at least one Subconn BH4F thru-hull that complies with this wiring diagram.