Do outfits do anything?

The majority of the outfits, such as the "Whale Hunter Outfit" and "Shark Hunter Outfit" appear to have no effect other than changing your appearance. Some, however, give your character bonuses. For example:

• Templar Armor: (Provides 25% Damage Reduction)

• Stealth Outfit: (Decreases Visibility and Improves Stealth)

• Mayan Outfit: (Deflects All Bullet Attacks)

• Hunter Outfit: (Reduces Animal Aggression)

These 4 are the only outfits I've found that are described as having any bonus associated with them.

See also:

IGN Assassins Creed IV Guide

Guide 4 Games Guide