Bouyancy Simple for a GameObject

using UnityEngine;
using System.Collections;

public class BouyancySimple : MonoBehaviour {

public float frequencyMin = 1.0f;
public float frequencyMax = 2.0f;
public float magnitude = 0.0025f;
private float randomInterval;

void Start () {
randomInterval = Random.Range(frequencyMin, frequencyMax);
}

void Update () {
Vector3 pos = transform.position;
pos.y += (Mathf.Cos(Time.time * randomInterval) * magnitude);
transform.position = pos;

//Vector3 angle = transform.eulerAngles;
//angle.y += (Mathf.Cos(Time.time * randomInterval) * 2);
//transform.eulerAngles = angle;
}

}