Positions quoted in the Preliminary Notice reproduced below are referred to an UNDETERMINED datum and are NOT COMPATIBLE WITH THIS ENC.
Some or all of the information contained in this Notice to Mariners may have been included in the ENCs affected.

3997(P)/20 PHILIPPINE ISLANDS — Sulu Sea — Reef.
Source: UKHO

	1. The reef at Arena Island is reported to extend W to approximate position 9° 14' .5N. , 120° 43' .3E.

	2. Mariners are advised to navigate with caution in the area.

	3. Charts will be updated when full details are available.

	   (UNDETERMINED DATUM)