Note: Not all locales have all Encounter levels. If you choose a locale with a low maximum EL, the random generator will default to the highest available EL level. Also, should the generated encounter appear to be too easy or hard for your group, adjust the number of creatures and/or class levels of patrol members and ship crews to make them appropriately challenging for your group. Or use to the next lower or higher EL level to generate the encounter.
Encounters for level 17+ are suggestions only and include creatures of very very high CR. By the time your group reaches these Encounter Levels, you should be using encounters customized for your group and campaign.