Of you go to the part of the ocean where megalopolis and great whites are (you must achieve gold rush in the process) you will become invincible to any attack and you can eat the Sharks and mini subs however you can but only when you get gold rush
To do this cheat and to get unlimited daily bonus is very easy but quite painfull. Step 1.. Get your first daily bonus. Step 2.. Leave game and double tap home button(iPhone) and stop game running in background. Step 3.. Change date and time settings to one day ahead. Step 4. Play Hungary shark Evolution again and get daily bonus. Step 5.. Rinse and repeat.