Cut long strips from carrot using a vegetable peeler. Trim strips into 3-inch triangles to resemble pennants. Place triangles into ice water for 15 minutes or until slightly wavy.
Spread rolls with mustard and mayonnaise, if desired. Place an olive slice on each end of pretzel sticks; place 4 sticks on each roll half to resemble portholes. Place lettuce leaves over pretzels; arrange turkey slices over lettuce.
Cut drinking straws into 6-inch lengths; insert straws into cheese slices to resemble sails. Insert straws into sandwiches.
Drain carrot triangles on paper towels. Insert a wooden pick through wide end of each carrot triangle; place picks in straws to resemble flags.
Serve with additional mustard and mayonnaise, if desired.