Images of species taken on the uppershore at Marazion, 01.02.10; and in a middleshore rockpool between Skilly and Roskilley, south of Newlyn, Cornwall. 05.08.11.
Giant gobies are a protected species in the UK. Their typical habitat are rockpools on the upper to middleshore, that are lined with green algae and where there are large boulders for them to retreat.
Because of the protection it would be wrong to try and catch them and put them in a bucket. My experience of them is that it is extremely difficult to net them anyway because of the size of the stones they hide under. Trying to net them may just stress or at worse damage them in some way.
They can be easily found and observed on the rocky shores on the Devon and Cornwall coast where they occur. Giant gobies would appear to love to bask in the sun, if disturbed you'll often hear a very large splosh in the pool beside you; which is a good sign the fish are there. The species, the largest Goby in UK Waters, can get up to 30cm in length. You'll be best able to see them, if they're hungry, by placing a piece of fish or shellfish in the pool near the rock they're under and waiting very patiently.
Giant gobies can easily be confused with large Rock gobies, that can be found in the same pools. By studying the images here you should be able to tell the difference without having to capture them. If you do find them they should be reported to the local Wildlife Trust, giving the date and place where they were seen and they type of habitat they were found in.
Scientific and European Names: Gobius cobitis, Giant goby, Gobi mawr.