Paul Elliott
Member
- Joined
- May 26, 2013
- Messages
- 16
- Fluid Motion Model
- C-28
Shipfinder and similar internet-based AIS tools are great for what they are, but as far as I'm concerned they are no substitute for an AIS receiver, or better yet, a transponder:
Internet-based tools rely on their being a receiver somewhere close by. These receivers are installed by hobbyists and sometimes businesses, and they may or may not have coverage where you need it. There are often large dead-zones with these network-connected receivers (I know, I have one myself.) An actual receiver on your boat will see all the AIS traffic within your line-of-sight, which is the area you should be concerned with.
Internet-based AIS tools will have a delay in the ship's data as it is updated. Often this delay is only a few seconds, but it can be much longer. When a ship is maneuvering or at high speed it broadcasts position reports more frequently, and these multiple reports are often filtered in the internet-AIS systems to keep the data-rate to a reasonable level. With an AIS receiver or transponder on your boat you will see each and every position-report that is broadcast (within your reception area).
Internet-based AIS is *not* a transponder. A receiver is very good, but a transponder is arguably worth the extra cost.
My opinion, but I've been working with AIS for many years now.
Internet-based tools rely on their being a receiver somewhere close by. These receivers are installed by hobbyists and sometimes businesses, and they may or may not have coverage where you need it. There are often large dead-zones with these network-connected receivers (I know, I have one myself.) An actual receiver on your boat will see all the AIS traffic within your line-of-sight, which is the area you should be concerned with.
Internet-based AIS tools will have a delay in the ship's data as it is updated. Often this delay is only a few seconds, but it can be much longer. When a ship is maneuvering or at high speed it broadcasts position reports more frequently, and these multiple reports are often filtered in the internet-AIS systems to keep the data-rate to a reasonable level. With an AIS receiver or transponder on your boat you will see each and every position-report that is broadcast (within your reception area).
Internet-based AIS is *not* a transponder. A receiver is very good, but a transponder is arguably worth the extra cost.
My opinion, but I've been working with AIS for many years now.