What you really need to worry about is the dreaded “water spike”. Ejecta, spike, ejecta, and spike. These pictures may not be reproduced, copied, edited, published, or uploaded to any Site(s) including Blogs without his written permission.) The physics behind water spikes is remarkably complicated and only recently has their formation been accurately described and simulated. Water spikes are the result of a symmetric air-cavity collapse just below the surface.