When dealing with larger, more heavily armed and armored ships, your best option is usually to close the distance and board for a direct confrontation with the enemy crew. It's better to risk a few wounds while using your party's combat abilities than to lose your ship altogether if you can't get the upper hand in ship-to-ship combat.
The problem is that the Defiant (or whatever boat you bought after the beginning of the game) takes automatic heavy cannon damage while you board, and crew injuries are virtually guaranteed. That makes the close-to- board maneuver a gamble that is often expensive and will have your crew out of commission at low morale while they heal.
If you really don't care for the ship-to-ship combat events at all, this mod negates all incoming damage during the close-to-board maneuver, so you can just jump straight into standard combat.