The subject line pretty much says it all but, for thoroughness' sake, I'll restate it here.

When attempting to do some underwater excavating I discovered that the shovel only digs 1x1 when the blocks it is targeting are under water. This is true both when they are deeply submerged as well as when at a depth of 1 block and mined while standing. Standing in the water or on adjacent blocks does not seem to make a difference.

Steps to reproduce:

1. Craft a Wooden Shovel (Mod version, 9x Vanilla Shovels to craft)
2. Attempt to clear dirt which is located under the water.

Fix pushed, sorry for the delay, was porting our other mods =D