By setting limits on the number of days purse seine vessels fish, the VDS is a management tool to limit fishing within sustainable levels. However it also has an economic objective of creating competition between Distant Water Fishing Nations (DWFNs) to purchase units of fishing effort in days, at the highest possible price.

To prevent or constrain technical changes in fishing power and efficiency that may lead to maintaining or increasing catches as a result of the implementation of the VDS, a fishing day under the VDS has been apportioned based on vessel length:

(i)    every fishing day by a purse seine vessel with a length overall of less than 50 metres shall equate to a deduction of one half of a fishing day;
(ii)    every fishing day by a purse seine vessel with a length overall of between 50 metres and 80 metres shall equate to a deduction of one fishing day; and
(iii)    every fishing day by a purse seine vessel with a length overall in excess of 80 metres shall equate to a deduction of one and one half fishing days.

The apportionment between vessel length and a fishing day can effectively be modified over time to account for changes in fishing power and efficiency.  This modification of the relationship between vessel length and fishing capacity, in addition to the ability to change the total number of days that can be fished over time provides the ability to change catch effort relationships.

When apportioning fishing days under the VDS, specific allocations have been made for regional fishing arrangements to which the PNA are a Party.  These regional arrangements are the States of Micronesia Arrangement for Regional Fisheries Access (FSMA) and the Multilateral Treaty on Fisheries between the Governments of certain Pacific Island States and the Government of the United States of America (US Treaty).