Make it so if your underwater riding a boat you run out of oxygen?

So if your boat is flipped upside down make it so you lose oxygen until you exit the seat and swim up to the surface

local bar = script.Parent.BarBG.Bar
local oxygenLabel = script.Parent.BarBG.OxygenAmount

local maxOxygen = 100
local currentOxygen = maxOxygen

local timePerLoss = 0.3
local chairwater = false
local isSwimming = false

local char = game.Players.LocalPlayer.Character
local hum = char:WaitForChild("Humanoid")


hum.StateChanged:Connect(function(oldState, newState)
	
	
	if newState == Enum.HumanoidStateType.Swimming then

		isSwimming = true
		script.Parent.Enabled = true
		
	elseif chairwater == false then
		isSwimming = false
	end
end)
char.Torso.Touched:Connect(function(hit)
	if hit:IsA("Water") and hum.Sit == true then
		chairwater = true
		isSwimming = true
	else
		chairwater = false
	end
end)


while wait(timePerLoss) do
	
	
	if isSwimming then
		
		currentOxygen = math.clamp(currentOxygen - 1, 0, maxOxygen)
		
	else
		currentOxygen = math.clamp(currentOxygen + 1, 0, maxOxygen)
	end
	
	
	if currentOxygen < 1 then
		
		hum.Health = 0
	end
	
	
	local barScale = currentOxygen / maxOxygen
	bar:TweenSize(UDim2.new(barScale, 0, 1, 0), "InOut", "Linear", timePerLoss)
	
	oxygenLabel.Text = currentOxygen .. " / " .. maxOxygen
	if currentOxygen == maxOxygen then
		script.Parent.Enabled = false
	end
end