How do you slow down the turn speed of an boat?

I made a boat and the when I turn it to left/right the turn speed.

This is a script for my boat

The Other Is set to :

BodyGyro : maxTorque : 10000000, 10000000, 10000000 X:10000000 Y:10000000 Z:10000000 P:3000

BodyPosition : D: 1250 maxForce: 0, inf, 0 X:0 Y:inf Z:0 P:10000

BodyVelocity: maxForce: inf,0,inf X:inf Y:0 Z:inf P:1250 velocity:0,0,0

seat = script.Parent
gyro = seat.BodyGyro
pos = seat.BodyPosition
vel = seat.BodyVelocity

pos.position = seat.Position
gyro.cframe = seat.CFrame
speed = 0
ready = true
wait()
seat.Anchored = false

function move(property)
	if property == "Steer" then
		if not ready then
			return
		end
		ready = false
		steer = seat.Steer
		while steer ~= 0 do
			steer = seat.Steer
			if steer == 1 then
				gyro.cframe = gyro.cframe * CFrame.fromEulerAnglesXYZ(0,-.1,0)
			elseif steer == -1 then
				gyro.cframe = gyro.cframe * CFrame.fromEulerAnglesXYZ(0,.1,0)
			end
			wait()
			vel.velocity = seat.CFrame.lookVector * speed
		end
		ready = true
	elseif property == "Throttle" then
		throttle = seat.Throttle
		while throttle ~= 0 do
			if throttle == 1 and speed < seat.MaxSpeed then
				speed = speed + 1
			elseif throttle == -1 and speed > 0 then
				speed = speed - 1
			end
			wait()
			vel.velocity = seat.CFrame.lookVector * speed
		end
	end
end

seat.Changed:connect(move)