Yup. You'd need a friggin' HUGE Coast Guard to effectively patrol the seaboard and the Great Lakes. Most of the patrol boats don't have long-term living quarters aboard, so you'd have to build at least five for each patrol station (and there's a bunch of those). Then you have to add in people to pay those patrol boat crews, feed them, provide base security, and so on, and so on...
If you were going to wildly exaggerate the size of the Coast Guard force we'd need, why didn't you say millions?
Gosh, I guess you don't LIKE being shown reality.
Get real.