You can walk through the water and over the landscape. I was going to turn this into some sort of game, but I just sort of gave up, so here is the environment by itself.
hide mouse:sync on:sync rate 60:autocam off:bg=rgb(185,190,215):backdrop on:color backdrop bg:fog on:fog color bg:set camera range 1,400
randomize 1:r=125:for x=0 to r:for y=0 to r:o=rnd(100)+155:ink rgb(o,o,o-50),0:dot x,y:next y:next x:get image 1,0,0,r,r
ink 16777215,0:cls:for x=1 to sqrt(r):dot rnd(r),rnd(r):next x:get image 2,0,0,r,r
make object plain 3,2,2
position object 3,0,0,1
texture object 3,2
ghost object on 3
lock object on 3
for x=1 to 2:make object plain x,4000,4000:color object x,bg:set object x,1,1,0,1,1,0:xrotate object x,90:next x
ghost object on 1,1:ghost object on 2
make matrix 1,1250,1250,64,64:set matrix 1,1,1,1,1,1,1,1:prepare matrix texture 1,1,1,1:randomize matrix 1,15:update matrix 1
ph#=2:position camera 500,ph#,500:rotate camera 0,0,0
wl#=5
do: for x=1 to 2:position object x,0,wl#,0:next x
mv#=(upkey()-downkey())*0.125/(((y#-ph#)<wl#)+1):move camera mv#
x#=camera position x():z#=camera position z():y#=get ground height(1,x#,z#)+ph#
position camera x#,y#,z#:if y#<wl#:fog distance 10:hide object 1:show object 3:scroll object texture 3,0,0.003:else:fog distance 300:show object 1:hide object 3:endif
turn camera right (rightkey()-leftkey())*1.75
sync
loop
EDIT: Added underwater debris effect.
