The Navy has ships AND boats.
By longtime traditional usage in the USN, submarines have always been referred to as "boats". In a similar vein, although not as longtime, Aircraft Carriers have long been referred to as "boats" as well and the term appears to have become pretty widespread.
I was going to say the same but somehow got caught up in work. I was stationed at the clinic at NAS Cecil Field, RIP, in the middle 90s and all the airdales called the largest warships in the world "The Boat."
Me: Where's your health record? ABH2 Wilson: It's still on the boat.
Hotshot Hornet pilot: "I need an up chit." Me: Where's your flight surgeon? "He's still on the boat." Me: umm, where's your airplane and why do you need an up chit?"
Here's my favorite: Me on the phone: Your flight surgeon isn't here. He said he would be at the squadron. Squadron XO in a loud voice to me in my clinic: "This IS the squadron and he
ain't here." Me: Not my problem XO, he works for you, not me. Click
I know the last dialogue didn't mention "The Boat" but as a non-aviation, surface and FMF HMC on a master jet base, I collected at least a chapter full of stories. Most pilots were cool and all our flight surgeons were top notch but there's a time and place to display one's arrogance. I know most of them earned that arrogance but so did I.
The coolest pilot while I was there was the base CO. A stud named Sam Houston. yep, Sam Houston.