Photos of tugboat wheelhouses frequently show an array of comm gear. I don't think that even 3 marine radios would be uncommon, in addition to satellite telephone. On US inland waters, a tugboat/towboat/pushboat may be monitoring 13 & 16 on different radios, as well as an onboard 'working' channel. I'm thinking that most commercial users would much rather buy one more radio than depend on scanning, for safety-of-navigation issues.
I've found one user of CTCSS on a marine channel in Hampton Roads, but am pretty sure it's the USN. Another user uses Ch-63 & 64, which are not authorized for use in the US. You may hear CTCSS on those channels, but they're not the marine user. They are local sheriff's offices, somewhat distant from the port.
73/Allen (N4JRI)
I've found one user of CTCSS on a marine channel in Hampton Roads, but am pretty sure it's the USN. Another user uses Ch-63 & 64, which are not authorized for use in the US. You may hear CTCSS on those channels, but they're not the marine user. They are local sheriff's offices, somewhat distant from the port.
73/Allen (N4JRI)
