Floating-like objects in Unity

FloatObject.cs

using UnityEngine;

/// <summary>
///     Represents a behavior script which will cause the object to float following a sine wave pattern.
/// </summary>
public class FloatObject : MonoBehaviour
{
    [SerializeField] private float _amplitude = 0.25f;
    [SerializeField] private float _frequency = 1f;
    private float _t = 0f;
    private float _y = 0f;

    private void Start()
    {
        _y = transform.position.y;
    }

    private void Update()
    {
        _t = (_t + (Time.deltaTime * _frequency)) % (Mathf.PI * 2f);

        var position = transform.position;
        position.y = (Mathf.Sin(_t) * _amplitude) + __y;
        transform.position = position;
    }
}