In order to affect third persons, every mortgage of a ship subject to this Chapter entered into prior to the time Chapter 9 of the Louisiana Commercial Laws becomes effective shall be by authentic act, or by private act, duly authenticated in any manner provided by law. A multiple original of every such act of mortgage shall be filed in the office of the recorder of mortgages of the parish where the mortgaged ship is to be constructed according to the terms of the mortgage instrument and also in the office of the recorder of mortgages for the parish of the mortgagor's domicile, if the mortgagor is domiciled in the state. If the mortgagor is not domiciled in the state, filing in the office of the recorder of mortgages of the parish where the ship is to be constructed according to the terms of the mortgage instrument will be sufficient. Upon receipt of the instrument the recorders of mortgages shall note thereon the date, hour, and minute of receiving it and shall record it in their respective offices. The recorder of mortgages immediately shall cause to be endorsed on the instrument his certificate of recordation. For these services each recorder of mortgages shall receive two dollars. Every security interest affecting a ship subject to this Chapter entered into after Chapter 9 of the Louisiana Commercial Laws (R.S. 10:9-101, et seq.) becomes effective shall be created and perfected in the manner provided under Chapter 9.