ranger58sb
Guru
An observation, from our trolling experience yesterday.
A relatively small powerboat crossed our bow yesterday at a reasonably high rate of speed, perfectly safe crossing... no problems. FWIW, it was named "Outrage" in its AIS transmission, so I make the guess that it may have been a Boston Whaler of that model.
I watched him visually, and also tracked him on the radar... and I was also able to follow him on the chartplotter via his AIS signal. (Not so common around here to see AIS on a small-ish vessel such as this... at least not so far).
His last transmission immediately before crossing in front of us was about 1/4-mile out at about 10 o'clock. His next transmission was about 3/8ths of a mile out at about 2 o'clock. IOW, he was traveling at about 5/8ths of a mile between AIS transmissions, and he crossed ahead of us -- and then some -- within the space of those two transmissions.
Visibility conditions were adequate. This was shortly after daybreak: cloudy, overcast, and slightly foggy in some areas... but nav lights on all the various vessels in sight were clearly visible, and visibility wasn't particularly hampered by weather conditions. The fishing crew I had aboard we're doing their thing at the time, with no significant input needed from me... so I was able to keep a sharp lookout with no distractions.
His track on the radar was obvious, although even that was a "dotted line" formed by multiple returns from the open array set to .5 NM max.
In significant fog, he may not have been visible to the Mark I* Eyeball at all those distances... and in heavy pea-soup, I wouldn't have been able to eyeball him at all. (And he likely wouldn't have been traveling at that speed in conditions like that.)
-Chris
A relatively small powerboat crossed our bow yesterday at a reasonably high rate of speed, perfectly safe crossing... no problems. FWIW, it was named "Outrage" in its AIS transmission, so I make the guess that it may have been a Boston Whaler of that model.
I watched him visually, and also tracked him on the radar... and I was also able to follow him on the chartplotter via his AIS signal. (Not so common around here to see AIS on a small-ish vessel such as this... at least not so far).
His last transmission immediately before crossing in front of us was about 1/4-mile out at about 10 o'clock. His next transmission was about 3/8ths of a mile out at about 2 o'clock. IOW, he was traveling at about 5/8ths of a mile between AIS transmissions, and he crossed ahead of us -- and then some -- within the space of those two transmissions.
Visibility conditions were adequate. This was shortly after daybreak: cloudy, overcast, and slightly foggy in some areas... but nav lights on all the various vessels in sight were clearly visible, and visibility wasn't particularly hampered by weather conditions. The fishing crew I had aboard we're doing their thing at the time, with no significant input needed from me... so I was able to keep a sharp lookout with no distractions.
His track on the radar was obvious, although even that was a "dotted line" formed by multiple returns from the open array set to .5 NM max.
In significant fog, he may not have been visible to the Mark I* Eyeball at all those distances... and in heavy pea-soup, I wouldn't have been able to eyeball him at all. (And he likely wouldn't have been traveling at that speed in conditions like that.)
-Chris