Yeah, okay - a "technical" hijack - it's a related question and as the second post on the thread asked "how are you receiving AIS"? I figured it was relevant.
So the "AIS Apps" use land-based clients that can have delays and so can't be relied upon for nav purposes....I get that....
But the word "application" as used by the OP does *not* necessarily exclude other means of receiving AIS
info than simply "iPad Apps" from iTunes.
And receiving AIS from either a dedicated receiver, or a VHF radio
with AIS functionality, are certainly "applications" that could be utilised to enable AIS overlays on an iPad
OK, so the OP did not ask "how can I get AIS onto my iPad", but that is the question I'm 'assuming' was asked. Shoot me.
Hence my query as to why there is a need to have effectively two GPS
units. You're paying for both of them, so if one is redundant, that's a *waste* of money
, isn't it?
From what I've been told by those in the know (offline) the iPads GPS
would need EITHER functionality added to a chartplotter
app (to send its GPS data wirelesly to the AIS/VHF radio), or a dedicated "feed GPS data via wifi
to external device" app, which it appears no-one has so far developed.
What I'm trying to get at is that 'dedicated brand name' AIS units - whether receiver only or Class b transponders, seem horrendously expensive, compared to Nav apps. $50 for a chartplotter
app; $200 for a dedicated AIS receiver, $1000+ for a Class b transponder.
What I was looking at was based on someone needing to buy both iPad
and VHF radio
*and* wanting AIS functionality, and finding the cheapest workable solution.
Ideally Class b, but in its absence, receive-only - hence why looking at the SH 2120 (for example).
a 2120 adds about $100 to the cost of similar good quality VHF-only radio, which appears to be cheaper than the cost of a low-end VHF radio plus a dedicated AIS-receiver (like an EM Trek B100 or AMEC CYPHO). And the low end VHF would likely not have DSC
functionality, so this is an added bonus.
So apparently cheaper than dedicated VHF plus dedicated AIS receiver.
But as others have acknowledged, the 2120 needs a GPS signal to show 'ownship' and thus the relevant local area shipping
(and to assist the DSC
So would a hockey puck
GPS + wifi-only iPad do the same job as the GPS-enabled iPad - and could this also be cheaper...??
Supplementary question: does anyone know if its posible for the GPS data form the iPad to be used by either a dedicated AIS receiver OR a VHF/AIS/DSC radio? Is my oinformant correct and this is currently "not possible" until someone invents/writes a sepcific "app" for the iPad to enable it?
So in the meantime, a SH 2120 (for example), plus puck
GPS, plus wifi-only iPad, would be cheaper than "dedicated VHF plus dedicated AIS receiver plus GPS-enabled iPad"...
And if so, then you'd only need a very simple NMEA
'bridge' (or router) to carry the merged AIS/GPS data to the iPad, with no need for the 'bridge' or 'multiplexer' to have a GPS function.
So this ought to be cheaper than than using a dedicated 'wifi bridge with GPS' such as the DMK Box 11A GPS at $500.
So my question basically is this - would this cheaper option require a separate "AIS app" as per the OP, or could the "chartplotter app" take it direct (eg: iNavX
And further supplementary: why does a 'receive only' AIS unit start from $200, while Class b tronsponders start fom $900.
Am I missing something here? Why is AIS so expensive?