Water and liquid CSS components are phenomenal for driving an atmosphere of focus. This trick utilizes absolute positioning to shoot out 3 expanding transparent borders simulating ripples hitting a pond face.

Generating the Rings

.water-card {
  background: #0284c7;
  position: relative;
  overflow: hidden;
}

.ripple {
  position: absolute;
  top: 50%; left: 50%;
  width: 20px; height: 20px;
  margin: -10px 0 0 -10px;
  border-radius: 50%;
  border: 2px solid rgba(255,255,255,0.6);
  opacity: 0;
}

/* Hover kicks off the cascade! */
.water-card:hover .ripple { animation: splash 2s cubic-bezier(0, 0.2, 0.8, 1) infinite; }
.water-card:hover .ripple:nth-child(2) { animation-delay: 0.6s; }
.water-card:hover .ripple:nth-child(3) { animation-delay: 1.2s; }

@keyframes splash {
  from { transform: scale(1); opacity: 1; }
  to   { transform: scale(30); opacity: 0; }
}

Hover directly over the center of the deep blue lake panel inside the Live Demo to see the rings burst outwards continuously!