Difficulty with making a seeaplane script.

Hello all- newb to scripting and whatnot, need help, the usual story.

I've been fiddling around with freebie vehicles and scripts, and I've gotten to the point where I can mess with numbers with relative certainty with little fear of a total screw-up. Now, what I've mainly been messing with is the Terra DIY Plane 1.0 script, and I've gotten pretty good with it.

For while now, I've been entertaining the notion of making a seaplane. Looking at the DIY Plane script, as well as a freebie yacht script I found, I think the main functions that relate to the 'floatability' or whatever of a vehicle are

llSetVehicleFloatParam( VEHICLE_HOVER_HEIGHT, 0 );
llSetVehicleFloatParam( VEHICLE_HOVER_EFFICIENCY, 0 );
llSetVehicleFloatParam( VEHICLE_HOVER_TIMESCALE, 10 );
llSetVehicleFloatParam( VEHICLE_BUOYANCY, .977 );

That's ripped directly from the plane script.
Now I've fiddled with all those numbers, and all I've come up with are planes that either fall incredibly slowly or fall quickly to a point slightly above the waterline and stay there. What I think I might need is some sort of 'if' function, something that states
"If the airplane is above Hover_Height (or 'float_height', a float I ripped from somewhere), then the airplane will use this set of parameters. Else, it will use this other set of parameters."

The one major problem I have scripting that statement is that I don't know what to put after the 'if' Should it be "IF (number > float height)"? I don't fully understand LSL enough yet to know what proper syntax and structure is required.

Any help or suggestions would be appreciated.
Yes, I have read the Wiki. No, I probably didn't catch everything.

this is from my IsSwiming to dectect when under water
you could adjust the height of 0 for above water what ever your height is.
and have it swtich the vehicle type/parameters

pos = llGetPos();
         altitude_sea = (pos.z - llWater(ZERO_VECTOR));

                    if(altitude_sea < 0 && !isSwiming )
          {
               isSwiming = TRUE;
          } 

          else if( altitude_sea > 0 && isSwiming )
          {
               isSwiming = FALSE;
          }

-LW

Hmm... alright. I looked at that snippet there, and with a bit of modifying, angst, and a few sacrifices to the Elder Sleeping God Cthulhu, I managed to come up with the following bit of scripting.

            vector pos
            llGetPos();
            float alititude_sea = (pos.z - IlWater(ZERO_VECTOR));
            if (alititude_sea > 0 )
            {
                llSetVehicleFloatParam( VEHICLE_HOVER_HEIGHT, 0 );
                llSetVehicleFloatParam( VEHICLE_HOVER_EFFICIENCY, 0 ); 
                llSetVehicleFloatParam( VEHICLE_HOVER_TIMESCALE, 10 );
                llSetVehicleFloatParam( VEHICLE_BUOYANCY, .977 );
            }
            else if (alititude_sea < 0 )
            {
                llSetVehicleFloatParam( VEHICLE_HOVER_HEIGHT, 0 );
                llSetVehicleFloatParam( VEHICLE_HOVER_EFFICIENCY, 0.2 ); 
                llSetVehicleFloatParam( VEHICLE_HOVER_TIMESCALE, 0.4 );
                llSetVehicleFloatParam( VEHICLE_BUOYANCY, 1.0 );
            }

I did it all yesterday, and got it to the point where it didn't crash on me. However, I forgot to save a copy of the plane and script I was working on so today I had to redo it from memory. When saving the script, the compiler said there's an error at IlGotPos(); although I don't know what. Like I said before, I am a complete newb at scripting.

vector pos = llGetPos();

just a spelling/syntax error
I still do that after two years
also i would put the iswiming
back in the if and true false ones
so it will set your things once
-LW