Free Swiming Fish Promblem

im using sensors to help guide a fish and im having trouble with my script now, nomatter what combination i use for sencing no moving objects i cant seam to get it to work right, the way i have the script now is it will keep going untill it notices something inrange of about 2m then it wil turn a random angle and head to the dirrection the water is open with no moving objects

plz dontresell/give away this script took me all week basicly to get this far

///////////////\\\\\\\\\\\\\\\\\\\\
//Created by Mrc Homewood\\
///////////////\\\\\\\\\\\\\\\\\\\\

vector fwd_vel = <14,0,0>;
vector roam_around;
float roam_range = 1;
float roam_delay = .6;
default
{
    state_entry()
    { 
        llSetText("FreeSwiming Fish Test",<1,1,1>,1); 
        roam_around = llGetPos();
        llSensorRepeat("", NULL_KEY, PASSIVE, roam_range, TWO_PI, roam_delay - llFrand(roam_delay / 60));
        llSetVehicleType(VEHICLE_TYPE_BOAT);
        llSetVehicleFlags(VEHICLE_FLAG_HOVER_UP_ONLY | VEHICLE_FLAG_HOVER_WATER_ONLY);
        // remove these flags 
        llRemoveVehicleFlags( VEHICLE_FLAG_HOVER_TERRAIN_ONLY 
                      | VEHICLE_FLAG_LIMIT_ROLL_ONLY 
                      | VEHICLE_FLAG_HOVER_GLOBAL_HEIGHT);
        
        // least for forward-back, most friction for up-down
        llSetVehicleVectorParam( VEHICLE_LINEAR_FRICTION_TIMESCALE, <2, 3, 2> );
    
        // uniform angular friction (setting it as a scalar rather than a vector)
        llSetVehicleFloatParam( VEHICLE_ANGULAR_FRICTION_TIMESCALE, 2 );

        // linear motor wins after about five seconds, decays after about a minute
        llSetVehicleFloatParam( VEHICLE_LINEAR_MOTOR_TIMESCALE, 5 );
        llSetVehicleFloatParam( VEHICLE_LINEAR_MOTOR_DECAY_TIMESCALE, 60 );

        // agular motor wins after four seconds, decays in same amount of time
        llSetVehicleFloatParam( VEHICLE_ANGULAR_MOTOR_TIMESCALE, 2 );
        llSetVehicleFloatParam( VEHICLE_ANGULAR_MOTOR_DECAY_TIMESCALE, 5 );

        // hover / float
        llSetVehicleFloatParam( VEHICLE_HOVER_HEIGHT, .1);
        llSetVehicleFloatParam( VEHICLE_HOVER_EFFICIENCY,.5 );
        llSetVehicleFloatParam( VEHICLE_HOVER_TIMESCALE, 2.0 );
        llSetVehicleFloatParam( VEHICLE_BUOYANCY, 0.5 );

        // halfway linear deflection with timescale of 3 seconds
        llSetVehicleFloatParam( VEHICLE_LINEAR_DEFLECTION_EFFICIENCY, 0.5 );
        llSetVehicleFloatParam( VEHICLE_LINEAR_DEFLECTION_TIMESCALE, 3 );

        // angular deflection 
        llSetVehicleFloatParam( VEHICLE_ANGULAR_DEFLECTION_EFFICIENCY, 0.5 );
        llSetVehicleFloatParam( VEHICLE_ANGULAR_DEFLECTION_TIMESCALE, 10 );
    
        // somewhat bounscy vertical attractor 
        llSetVehicleFloatParam( VEHICLE_VERTICAL_ATTRACTION_EFFICIENCY, 0.5 );
        llSetVehicleFloatParam( VEHICLE_VERTICAL_ATTRACTION_TIMESCALE, 2 );

        // weak negative damped banking
        llSetVehicleFloatParam( VEHICLE_BANKING_EFFICIENCY, 1 );
        llSetVehicleFloatParam( VEHICLE_BANKING_MIX, 0.1 );
        llSetVehicleFloatParam( VEHICLE_BANKING_TIMESCALE, .75 );

        // default rotation of local frame
        llSetVehicleRotationParam( VEHICLE_REFERENCE_FRAME, <0, 0, 0, 1> );
    }
    sensor(integer count)
    { 
        vector facing;
        vector dir;
        float dist;
        integer n;
        integer selected; 
        dist = roam_range + 1;
        for(n=0; n<count; ++n)
        {
            dir = roam_around - llDetectedPos(n);
            if (llVecMag(dir) < dist)
            {
                dist = llVecMag(dir);
                selected = n;
            }
            dir = dir % llRot2Up(llGetRot()) + roam_around;
            facing = llRot2Euler(llRotBetween(llRot2Fwd(llGetRot()), dir));
            facing.x = 0.0;
            facing.y = 0.0;
            llRotLookAt(llGetRot() * llEuler2Rot(facing), 1.0, 0.2);
            llSleep(0.2);
            dist = llVecMag(dir);
            if (dist < 1.0)
            {
                dir = llGetPos() - roam_around;
            }
            llSetStatus(STATUS_PHYSICS, TRUE);
            llSetVehicleVectorParam(VEHICLE_LINEAR_MOTOR_DIRECTION, 0.6 * fwd_vel);
            for (selected = llFloor(dist); selected > 1; --selected)
            {
                llSleep(0.25);
            }
            llSetVehicleVectorParam(VEHICLE_LINEAR_MOTOR_DIRECTION, ZERO_VECTOR);
            llSetStatus(STATUS_PHYSICS, FALSE);
            llStopLookAt();
        }
    }
    no_sensor()
    {
        vector facing;
        vector dir;
        float dist;
        integer selected;

        {
            facing.x = 0.0;
            facing.y = 0.0;
            facing.z = llFrand(TWO_PI) - PI;
            dir = ((((integer)llGetTime() % (integer)roam_range) + 1) * facing) * llGetRot();
            llRotLookAt(llGetRot() * llEuler2Rot(facing), 1.0, 0.2);
            llSleep(0.2);
            dist = llVecMag(dir);
            if (dist < 1.0)
            {
                dir = roam_around - llGetPos();
            }
            llSetStatus(STATUS_PHYSICS, TRUE);
            llSetVehicleVectorParam(VEHICLE_LINEAR_MOTOR_DIRECTION, 0.6 * fwd_vel);
            for (selected = llFloor(dist); selected > 1; --selected)
            {
                llSleep(0.1);
            }
            llSetVehicleVectorParam(VEHICLE_LINEAR_MOTOR_DIRECTION, ZERO_VECTOR);
            llSetStatus(STATUS_PHYSICS, FALSE);
            llStopLookAt();
        }
    }
} 

I'm not sure what you expect this to do or not do. I tried one in open water and it just sort of twitched around facing different directions without actually going anywhere, except to rise in several steps to near the surface. I did notice that the "physical" check box kept flickering it turned on and off so frequently.

ya it turns physical on and off when it chancge dirrections it will goin in random dirrects every few seconds