Here's some steam powered boats for early 1900s British warships. There are 3 sizes: 40', 45' and 51' launches.
The prototypes were printed with o.25mm layers up to a 13mm height. Above 13mm 0.1mm layers were used.
The cradles and the circular pours at the bow and stern are separate parts. So if you don't want them, you can split the .stl and delete the parts you don't want.