These are just the ones I found in my quick search: Tyvar's Stand, Legolas's Quick Reflexes, Loran's Escape, Shore Up, Blacksmith's Skill, Royal Treatment, and Blossoming Defense
The only format that you can play Dig in these days is as a one-of in Vintage or Commander
But Geological Appraiser, as well as instants and sorceries like Contest of Claws, need to resolve for the extra spell
Once again, I suggest you playtest your deck a few times and notice if you often have too much or too little mana
A 3-mana 3/4 is immense by blues standards and it comes with indestructible and some card draw to back up the pressure it provides
Instead of needing an enchantment to grant this to your creatures, just make some creatures that already have the ability