Potchip nailed it. I am not strictly 1/700, nor do I think potchip might be either.
But the first point is a great one. The rule of cubes gives a volume of 1/2 x 1/2 x 1/2 in a scale half the original, or 1/8 the volume of the original.
And I convert the ones I build to full hull. At 1/700 the draft of a ship is usually somewhere between 1/4" and 1/2". I just cut a piece of basswood over thick, trace the outline of the hull at waterline, and shape it following whatever information I have.
Rudders and shafts are easy; all kinds of props can be found in 3D print word. Left hand, right hand, four blade, five blade and on.
Plastic kit availability isn't really much more than in 1/350 I think, but in resin there is so much. I have three different classes of CL cruisers from the USN in World War Two. Two are plastic; Dragon releases of older Pitroad/ Skywave, and one is resin.
About the only negative I see is that aircraft are fussy, and decal app is a real lesson in exercising the zen mind. Sometimes I'll just do the bigger ones.
I second the recommendation.
Bill