Here's a list of your stops - I'm only including the ones that are right on the beach, which leaves out a few, nice roadside bars, but that's ok, we have plenty to work with.
Coco Locos is the first one you come to on the north side of the bridge, located in the condo complex of Villas del Rio, followed by Kama Lounge right next door, and then Feliz Bar and Grill in The Cloisters.
Jolly Roger's Beach Bar, one of my absolute favorite bars, is next, but they're closed until someone new takes over and reopens it. (I think Claire will still be selling her special edibles, so that's good!)
The Palapa Bar and Grill is about a 15 minute walk from Jolly Rogers, followed by AkBol - my most recent go-to place for a cold beer and affordable meal (try the Salbutes or the Falafel Burger)
The sexy, swim up bar at Grand Caribe is next... You might not want to spend too much time drinking at the fancy resorts if you're budgeting this bar hop, the prices increase the further north you get. (Don't worry, there will still be some bars that have $5.00bz beers and local rum drinks)
I've never been to Lazy Croc BBQ, but I hear good things about it and they have a sign on the beach, so they get a spot on my list.
Aji Tapa Bar and Restaurant is your next stop - I've only been there once on a dinner "date," and I remember a romantic atmosphere (soft music, candles) but it's totally fine to stop by there all sweaty in the afternoon and drink a beer. Maybe clean yourself up a bit if you're going to go back for dinner.
There's a bar open to the public at White Sands Cove Resort that you can check out - they have a Happy Hour sign on the beach (Happy Hour 1-5 Daily) and then pop on over to Capricorn Resort, Restaurant, and Bar for your next one.
It might be hard to continue bar hopping once you make your stop at Captain Morgan's Retreat - the pools are great and it's cool to just stay there all day, swimming, drinking, eating... but keep going, you still have another three and a half miles to go.
I'm not completely sure if the bar at Coco Beach Resort is still open to the public or not, but you're going in, anyway. Same deal with Belizean Shores Resort, just stop in real quick and get a roadie, because you won't get to the next bar until you reach the O Restaurant at Las Terrazas Resort and Residences.
Dinner Special - Indian.
I spent too much time wondering, "Indian what?? Curry? Kofta? Samosa??"
It still bothers me. Even, "Indian Food" would work for me....
Moving right along, you've got stops at Rendezvous Restaurant and Winery, the bar at Ambergris Divers Resort, and then, another one of my favorites, the Rojo Lounge.
By now, you should be drunk - but if you want to keep going for about one more mile, you can stop at Matachica Resort and Spa (expensive) Jambel's Jerk Pit (looks shadey, therefor, awesome) and then the beautiful and friendly (and also slightly expensive) Portofino Beach Resort, where you're welcome to enjoy your drinks at the pool.
That's, like, 22 bars right there - make sure you drink some water while attempting this challenge, and let me know how you do :)