SizeCategories

For size categories of this... magnitude... AC and TL mods are only relevant if your size category is within 7 ranks of your target's. If you're smaller, you are eventually guaranteed to hit. If you're larger, you are eventually guaranteed to miss. This is only for point attacks; larger vessels can still hit with area attacks if you're within the danger zone (which you likely are).

Now.

HP increment = 10% of the HP. CT = 20% of HP.

.