In every mission file in MISSIONS\EpisodeX folders a line can be found like
environment.set("Episode3mission1.xml")
which means that the mission environment is specified in the "Episode3mission1.xml" file. These environment files are located in ENVIRONMENTS folder.
If you open one of those files (say, Episode3mission1.xml) in the text editor, two section for DirectX 10 and DirectX9 can be found which start after
<dx10> and
<dx9c>, respectively.
Subsections
<Sea> in those sections set the sea state.
Parameters:
<water_mode val="4" /> should be set to
4 for DirectX10 and
3 for DirectX9.
<amplitude val="0.4" /> specifies the wave amplitude.
<height_quad_scale val="8" /> is tile size. It is multiple of 2, i.e. can have values
2,4,8,16. Value
2 corresponds to the largest tile and to the longest wave.
One can also play with the value of the
<height_period val="4" /> parameter.
You can try such sets of parameters (tested for DirectX10) as
<amplitude val="2.4" />
<height_quad_scale val="2" />
<height_period val="5" />
or
<amplitude val="1.4" />
<height_quad_scale val="4" />
<height_period val="4" />
and see if you like that. But in these cases, the waves are too big for PT-boats.