The green/yellow cable marked BLU runs from the copper strap in the lazarette to a ground connector at the navstation where without an SSB (BLU) installed it is connected to the bonding wire. I disconnected the BLU cable from the ground/bonding connection and connected it to the earth on the transceiver...yes the transceiver.
Then at the lazarette end I cut this cable and connected both ends to the ground on the antenna tuner. So, now we have both the transceiver ground and the tuner ground connected to the copper strap in the lazarette which in turn is connected to the SSB ground plates on the skeg.
This is what the ICOM manual instructs you to do.
The transceiver and antenna tuner MUST have an adequate RF ground connection.
The transceiver is NOT connected to the ships bonding.
BUT because internally the ICOM 12v -ve is connected to the ICOM ground, the negative side of the power supply must be isolated from the ships power -ve otherwise there will be a circuit through the seawater from ships negative to ships bonding...which is not allowed in the Amel system.
This can be accomplished by using an ISOLATED 24-12VDC converter (expensive) or with a non-isolated converter (inexpensive) and a relay in the -ve 24V supply to the converter such that this connection is only closed when the SSB is on. The small amount of time the SSB is on is nowhere near enough to cause a problem.