Just so you know... I'm from Vesper Marine
I agree on the clutter problem. I've been experimenting for quite some time with different filters for reducing the number of targets displayed so there isn't a confusing mass of vessels. The same thing applies to alarms. Nuisance alarms are annoying and just cause people to switch them off. For that reason, on my boat I don't use proximity alarms very much. I prefer to use a CPA/TCPA alarm
but suppress it with various things like not triggering for stationary targets, etc.
I think the comment about not caring about targets moving away or not posing a collision danger
is really important to reducing clutter on the screen
and allowing me to focus on the targets that are most important.
Awhile ago someone suggested to me to show a graphical representation of whether a target will pass ahead/astern or port/stbd. I liked that idea and it's worked out well.
If you go with a dedicated display that also outputs the AIS data you can also do overlays on other devices if/when you want to. You can run them at different scales and I often find that the scale I use for navigating isn't the same scale I want for collision
avoidance. But I like the redundancy of a dedicated display and the ability to see what's around me at a quick glance. Often I prefer to switch off power-hungry devices like plotters and computers
. It's personal preference I guess, but I find that AIS alerts me to targets I don't see initially, so I don't want to rely on switching things back on when I see lights.
Also, someone mentioned an anchor alarm
... I've been thinking about this for awhile. It's a bit off-topic but it's related to AIS because an AIS transponder "knows" where your GPS
antenna is located on your boat and that's one of the missing bits of info an anchor
alarm needs to know.
Regarding antenna height... I've experimented a lot recently with different antenna heights. I find I get adequate range for collision avoidance with the antenna on a stern rail, but I get much greater range by raising the antenna to a spreader or better yet the masthead. But I definitely wouldn't recommend mounting two antennas at the masthead.
I don't mean for this to be a product plug
but just wanted to answer the questions and share my experience. I hope that's ok.