Can I count birds seen offshore?

Again this is really up to you, but note that authorities typically have guidelines for what they consider part of their recording area.

In a British context, any birds seen from land are countable. For birds recorded from pelagic boat-trips, we would recommend that the sea areas considered by the BOURC should be used for British lists. A definitive map is available as part of the BOURC 35th Report (April 2007) . Essentially, the boundary lies 200 nautical miles (370 km) offshore, except where the median line between two countries is less than this limit.

For other countries, unless specific guidelines exist, we suggest you follow a similar rule. You can always add a comment to the record to indicate the circumstances for such sightings.