Chicago's Independence Day fireworks show is, for some reason, on July 3rd. This show is truly extraordinary—this coming from a guy whose senses have been dulled by watching fireworks twice a week for a decade. Hundreds of thousands of people show up to watch the show. From the water, the two most popular locations are inside and outside Monroe Harbor.
Regardless of where you will be watching from, the key is to get out early. Very early. The Chicago Harbor Lock, the mouth of Monroe Harbor, and movement within Monroe Harbor will all shut down before the fireworks. The exact times are always in flux and appear to be up to the Coast Guard's whim. The fireworks themselves usually start between 9:00 and 9:45.
Coming from the River
If you will be headed through the Chicago Harbor Lock from the Chicago River, the lock usually shuts down a half hour before the start of the fireworks, so about 8:30pm. But there are often long lines to get into the lock. Tour boats and any government vessel has the right of way over recreational vessels, so you might have to wait a couple of revolutions before going into the lock. In addition, the fireworks barge is considered hazardous cargo, so no one may accompany them into the lock. You should get to the lock by 6:30pm at the very latest to ensure you'll have enough time to make it to the Lake.
Watching from the Lake
The fireworks barge will set up at the north side of the Monroe Harbor breakwall. People will be anchored outside the harbor in the morning to get a good spot. Since the Fireworks shoot up high into the sky, though, anywhere is a good spot to see them. It's just a matter of how close you wish to be and which buildings you see directly behind the fireworks. There will be a six hundred foot security zone around the barge, so don't set up too close, or boats with flashing lights will kick you out.
Watching from Monroe Harbor
You'll want to get there very early. If you arrive after 5:30pm, you probably won't make it to your boat if you're on a mooring. The Tender Service is scheduled to shut down at 7:00pm, and the line just to get to the tender dock will delight you with an hour-and-a-half wait. The mouth of the harbor is scheduled to shut down at 5:30, which means no boats will be allowed in or out until after the fireworks. If you plan on picking people up from the touch-and-go dock, do so by 6:30. All movement in the harbor will be shut down by 7:00pm, and there is typically a line of boats waiting to get to the touch-and-go. Furthermore, the pump-out dock will be shutdown by 3:00, so that's not an option to meet passengers.
After the fireworks
Don't be in a hurry, because you'll go nowhere fast. Even if you manage to get back to shore right away, you'll still sit in automobile traffic for an hour downtown. If you need to go back through the locks, you'll probably wait 45 minutes minimum before you can enter. The tour boats go first. That's one full lock. Then the fireworks barge gets there. Another full lock. Maybe some more tour boats and police boats. Perhaps one or two recreational boats. That's another full lock. Then you, as well as a few hundred other boats all jockeying for position.
No matter where you dock, It's best just to sit and relax at anchor, or float gently for a while and avoid the danger of hitting another vessel every few feet, as they scatter in every direction like ants at a picnic.
If you're in Monroe Harbor, tender service will resume as soon as the fireworks are over. But don't call for a pick up. They won't take your call. Just turn on your mastlight, be ready to go, and be prepared to wait. If you're lucky, you'll get a pickup within 30 minutes. If you're unlucky, make it 3 hours.
Boating under the influence
This is a real infraction. The legal limit is the same for driving a car, .08. It will be enforced this weekend. So don't drink and boat.
Be safe and have fun.