The closing speed makes the difference. Which is also complicated for the little boats on the probably rough open seas where they'd encounter the carrier group. Carrier groups travel in miles-wide formations. Even if your first warning was your support-ships getting hit you'd still have minutes to react to the incoming threats. Time to get multiple aircraft up, set the guns to the right mode for targeting ships, etc.

It sounds like its the result of arbitrary rules letting you to attack someone by moving into their hex, etc. I don't think you'd get this result with a real-world battle exercise, where soldiers had to drive the boats tens of miles off-coast in radio silence for a coordinated attack on a hyper-aware enemy.