Need help with a sea plane script

Ok heres the issue, I was trying to make a float plane for a friend and when I try to get to float on the water with the code below it bounces off the water and I cannot figure out what I am doing wrong to make it float like a sea plane .
Any help would be apprecated

        vector mpos = llGetPos();
        float sea = llWater(ZERO_VECTOR) + 2.5;
        if(mpos.z > sea)
        {
            llSetVehicleFloatParam( VEHICLE_HOVER_HEIGHT, 0 );
            llSetVehicleFloatParam( VEHICLE_HOVER_EFFICIENCY, 0 ); 
            llSetVehicleFloatParam( VEHICLE_HOVER_TIMESCALE, 10 );
            llSetVehicleFloatParam( VEHICLE_BUOYANCY, .977 );
        }
        if(mpos.z < sea)
        {
            llSetVehicleFloatParam(VEHICLE_HOVER_HEIGHT, llWater(ZERO_VECTOR));
            llSetVehicleFloatParam(VEHICLE_HOVER_EFFICIENCY, .5);
            llSetVehicleFloatParam(VEHICLE_HOVER_TIMESCALE, .1);
            llSetVehicleFloatParam(VEHICLE_BUOYANCY, 1);
        }

Try increasing the hover efficiency.