The Cumbre Vieja volcano in the Canary Islands has received a lot of attention as a potential mega-tsunami generator. The premise is that it is a steep sided, active volcanic island with identified zones of weakness running approximately north-south that if she blows may result in a large, fast moving landslide failure on the southwest side of the island. This is termed a flank collapse. Early work suggested that this flank collapse could cause a tsunami event that would reach the southeast US about 8-11 hours after the failure. Along the Carolina and Florida coast with a complete rapid detachment of the landslide, initial modeling suggested 25-30 m of water will come ashore. (http://www.geo.arizona.edu/~andyf/LaPalma/doomsday.html)
With time, additional analyses and additional capabilities, these numbers have changed significantly. In the most recent studies (Harris, Grilli et.al. 2013) the times are shorter and the water height smaller. We are now at 6.9 hours and about 3.25 meters in Florida.
Cumbre Vieja has erupted several times in the recent past, in 1585, 1646, 1677, 1712, 1949 and 1971. The magma source for this volcano is deep and there has been only relatively minor seismic activity on the island. The next eruptions may tell the tale. If they are relatively low energy eruptions through existing vents, the opportunity for a flank collapse is low but the opportunity for gathering more information is high. If the next event is significant, keep the boats handy if you are a US East Coaster.