This is good for people flying..

Flightradar24.com

This is good for people sailing.
http://www.marinetraffic.com/ais/

Bookmarked for playtime !

Thank you, T&I and Jonboy.

I'd have thought it was of much more use for people on the ground in order to keep an eye on people who are flying.

Keeps the terrorists in touch with their target?

have been using it for about 3 years or so but for some reason FlightRadar24 is not omnipresent, I have flights that fly over/near the village that do not come up - they are not military.
also it can depend on the transponder being turned on/off, Malaga flights turn off as soon as they land but if you look at other places - Hong Kong for example you can see the transponder sitting on the ground along with a number of aircraft. (and that is a scary area to watch, letalone to fly)

followed one aircraft that was squarking from Rota to Eastern Europe.

Similarly with Marine traffic, not all boats are fitted with the equipment.
I have also been using this for some years and can watch the boats from my terrace and use it if possible when I see something of interest.

Anybody know the name of the ship that is parked halfway up a hill to the northwest of Barcelona as shown on marinetraffic.com ?

Puente de Trucha ?

The Ark

Keep an eye on the weather

Yes, it must be useful for you especially if you want to get a good photo. I have also been using marine for several years, find these progs of great interest in the same way as I have the use of HF commercial and amateur radio. Find they extend the mind from its immediate world to the greater forum of world trade. We are too centred on RYR or EZY and the parochial flights to/from our local Spanish airport and yet they are flying in/out of such aiports from all over Europe.
and then there is Singapore Airlines flight from Brazil to Singapore via Barcelona

I recall a case a few years back where I believe a satellite picked up on a maritime emergency transponder beacon.

The emergency services were alerted, but were later somewhat surprised to find that the signal was coming from a boat sat on a trailer on someones driveway in the midlands, many miles inland.

Been using it on my smartphone for a long time. It's great. Fascinating and reveals a lot about the incredible air transport system. Makes you realise how incredibly safe air travel is.

Ref my earlier post:-
I have just been watching this vessel and an unidentified green and white vessel playing in Gibraltar waters

P24 06022

Ship Type: Military Ops
Length x Breadth: 8 m X 3 m
Speed recorded (Max / Average): 29.6 / 14 knots
Flag: United Kingdom [UK]
Call Sign: 2FWO4
IMO: 0, MMSI: 235094838
Last Position Received
Area: Gibraltar
Latitude / Longitude: 36.1312° / -5.3640° (Map)
Speed/Course 13.5 knots / 0Ëš
Currently in Port: GIBRALTAR
Info Received: 0d 0h 1min ago (AIS Source: 841)

I wonder what the green and white vessel was

an alternative is
http://www.radarbox24.com/

The signal seems to be coming from in, or near, the University of Barcelona (my netbook is a bit old and probably inaccurate). They may be using it for training purposes. I read somewhere that Barcelona is Spain's centre of excellence for navigation - ever since one of the locals bumped into a Caribbean island and declared it India. Ganja has that effect.

They also have, in Barcelona, the Avinguda del Paral.lel which, as it's name suggests, is an avenue that runs parallel to the line of latitude and messes up the street plan, just for the sake of whimsy. Barcelona's like that.