Those who wear (or have worn) dolphins call them boats. The press calls them all kinds of things, including "ships".
If this seems petty, go and call a Canadian a Yank or a Kiwi an Aussie, tell a baseball or cricket player it's a nice stick, etc. You will see that people take their labels quite seriously, despite the fact that frequently they are colloquialisms or unofficial.
The people with no interest, including the press, don't care and thus are ignorant of convention. If you look up the definitions of ship and boat, you will see that there is actually no standard, it's all down to convention.