Just spent 45 minutes writing a reply as to why the Merlin HM1 is the greatest thing since sliced bread, only to be told I wasn't logged in.
So I'll just say this.........Merlin HM1 replaces Sea King HAS6. Contrast and compare them, particularly in terms of sensor capability.
Merlin
Sea King
All the senors are hugely more capable. The area of sea that can be sanitised by a Merlin is several times larger than that of a Sea King.