unruffled

providing or experiencing physical discomfort

• “an uncomfortable chair”
• “an uncomfortable day in the hot sun”

(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”
• “a lake of tranquil blue water reflecting a tranquil blue sky”
• “a smooth channel crossing”
• “scarcely a ripple on the still water”
• “unruffled water”