Nothing too exciting... I sailed over to do the Fastnet Race in 2009, and since guns are tightly regulated in the UK and since the barrel is considered the S/N part there, I replaced the barrel when I got back to the States. We sailed by a Portuguese Man-o-War jellyfish every 10-15 minutes, so there were plenty of targets to keep from boredom. Given the 3D movement of the boat and the targets, I didn't get many hits.
When we stopped off at Horta, in the Azores (a territory of Portugal) I declared it to the customs agent... and was invited rabbit hunting with pellet rifles on his uncle's farm a few days later!