public void CreateLocalPlayer();
{
    //Notice the differences from PhotonNetwork.Instantiate to Unitys GameObject.Instantiate
    GameObject newShipObject = PhotonNetwork.Instantiate();
        "Ship",
        Vector3.zero,
        Quaternion.identity,
        0,
        instantiationData
    );
}

void OnJoinedRoom()
{
    CreateLocalPlayer();
}