From NOAA

A stunning graphic of tsunami wave-heights from last night's Japanese earthquake, as captioned at NOAA's web site:

Tsunami Wave Height Model Shows Pacific-Wide Impact

Model runs from the Center for Tsunami Research at the NOAA Pacific Marine Environmental Laboratory show the expected wave heights of the tsunami as it travels across the Pacific basin. The largest wave heights are expected near the earthquake epicenter, off Japan. The wave will decrease in height as it travels across the deep Pacific but grow taller as it nears coastal areas. In general, as the energy of the wave decreases with distance, the near shore heights will also decrease (e.g., coastal Hawaii will not expect heights of that encountered in coastal Japan).The second image shows the depth of the Pacific Ocean floor. Notice the similarity between areas of low wave height and deeper areas of the ocean.An animated view can be seen here.

The legend only goes to 240cm, which is roughly seven and three-quarters feet.  We KNOW the tsunami that wrecked the coast at Sendai and beyond was much higher than that.