• Yacht registration certificate
• Crew list

There is the usual ban on importation of items that you see in some, if not all, countries, i.e. firearms, obscene materials and drugs with no prescriptions. What are notel below are the uncommon ones:

• Written or printed article in any form containing any matter advocating or inciting treason, rebellion, insurrection or sedition against the Government of the Philippines, of forcible resistance to any law of the Philippines, or containing any threat to take the life of or inflict bodily harm upon any person in the Philippines.
• Articles, instruments, drugs and substances designed, intended or adapted for preventing human conception or producing unlawful abortion, or any printed matter which advertises or describes or gives directly or indirectly information where, how or by whom human conception is prevented or unlawful abortion produced.
• Any device or articles used for gambling.
• Lottery and sweepstakes tickets except those authorized by the Philippine Government, advertisements thereof and lists of drawings therein.
• Any article manufactured in whole or in part of gold, silver or other precious metal, or alloys thereof, the stamps, brands or marks of which do not indicate the actual fineness or quality of said metals or alloys.

Harbor fees - Private, non-commercial pleasure yachts are exempted from arrival and departure port fees.

Once the entry procedures have been completed, foreign pleasure yachts are allowed to stay in the Philippine waters indefinitely without incurring import duty and tariffs provided they are not sold while in the Philippines.

Addendum: I should remind that "copied" dvds and Cds are also prohibited.