unity underwater game

[system]

hello good day! i'm new to unity, i created a timer for my game, and my game includes being underwater. I put the timer inside a GUI text. I want to decrease the HP for every 5seconds underwater. here's the code.. tnx for your help!

private var passedTime ; 
private var minutes : int ; 
static var seconds : int ; 
private var startTime = timeVar; 
private var startTime2 = timeVar; 
private var startTime3 = timeVar; 
private var quitGameOverP : boolean =true; 
var secondo ; 

function Update() 
{ 
if(id==true){ 
var theTime : String ; 
var timer ; 
if (GUIPrompt.hard== true&& GUIPrompt.medium == false && GUIPrompt.easy == false) 

{ 
timer = startTime ; 
} 

else if (GUIPrompt.medium== true&& GUIPrompt.hard ==false && GUIPrompt.easy == false){ 
timer = startTime2 ; 
} 

else if (GUIPrompt.easy== true){ 
timer = startTime3 ; 
} 

passedTime = timer - Time.time ; 

minutes = Mathf.Floor(passedTime / 60) ; 
seconds = Mathf.Floor(passedTime % 60) ; 

guiText.text = String.Format ("{0:00}:{1:00}", minutes, seconds); 
}

[Anxo]

Thats a lot of code, why not just say

private var Health = 100; private var UnderWaterTime : float = 0; private var UnderWater : boolean = false;

if (UnderWater){

UnderWaterTime +=1 * Time.deltaTime; if ( UnderWaterTime >= 5){ Health -= 10; UnderWaterTime = 0; return; }

} not tested but something along that line should work.

[Statement]

I think the following code could become a simple skeleton. I added a lot of comments, some are placeholders and some are intended usage. Basically the script enters a coroutine loop that wait until player is below water, then start a drowning sequence which is escaped by surfacing, to get air. I haven't tested this code, but I checked it for any compile errors.

I make use of InvokeRepeating to start the drowning method callback after 20 seconds, and OnDrowning should be called every 5 seconds after the initial 20 seconds have passed.

function Start()
{
    while(true)
    {
        yield WaitDive();
        OnDive();
        yield WaitSurface();
        OnSurface();
    }
}

// Called once every 5 seconds, 
// started 20 seconds after dive.
function OnDrowning()
{
    // Subtract health
    // Add audio feedback (swallow water)
    // Add visual feedback (flashing screen)
    // If death, remember to call CancelInvoke.
}

// Called when we are going into water.
function OnDive()
{
    // Add audio feedback (bubbles)
    // Add visual blur feedback
    // Start drowning after 20 seconds    
    InvokeRepeating("OnDrowning", 20, 5);
}

// Called when we are coming out of water.
function OnSurface()
{
    // Add audio feedback (gasp for air)
    // Remove visual blur feedback
    // No longer in a drowning state, cancel.
    CancelInvoke("OnDrowning");
}

// Obviously you need to fill in this gap.
function IsUnderwater() : boolean
{
    return false; 
}

// Helper that wait until is under water.
function WaitDive()
{
    while (!IsUnderwater())
        yield;
}

// Helper that wait until is over water.
function WaitSurface()
{
    while (IsUnderwater())
        yield;
}