unruffled

adjective

1. 1

   (of a body of water) free from disturbance by heavy waves

   a ribbon of sand between the angry sea and the placid bay

   the quiet waters of a lagoon

2. 2

   free from emotional agitation or nervous tension

   the waiters were unflurried and good natured

   with contented mind and unruffled spirit"- Anthony Trollope