"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"
"spoke in a calm voice" "remained calm throughout the uproar" "he remained serene in the midst of turbulence" "a serene expression on her face" "she became more tranquil" "tranquil life in the country"