How do you burn the longboats?

I’m probably missing something really obvious but I can’t seem to get close enough to burn the longboats. How can I get those ships to burn? Thank you for your help! I love this game!
The forum for all Redshift games.
http://www.linux.redshift.hu/forums/
http://www.linux.redshift.hu/forums/viewtopic.php?f=44&t=5486
Unc B wrote:I’m probably missing something really obvious but I can’t seem to get close enough to burn the longboats. How can I get those ships to burn? Thank you for your help! I love this game!