I'm a single mom, (age 50 but I act 49.5) & fairly handy with tools. My teen son wanted a pontoon boat for years. He always wanted to operate an ice cream boat on the Intracoastal Waterway where we live in NC. Since he turned 15 this year, it was time for him to get a job, and this is the job he wanted. He showed me he was willing to do the work, so we searched and found the perfect 24' pontoon... an older one with a nearly-new motor. The carpet and canvas top are teal, which worked well for us. We did not find the boat until mid-May, so weren't able to get it ready early in the season. We rushed and got it ready by July. He's now been on the water selling a few weeks, and it's been great.
Down the road, we might be able to do a full reno of the boat... or maybe I'll do that when he's off to college (altho he says he still wants to sell ice cream in summers then... he absolutely loves it! But I thought our quick fixes might interest some people on this board.
I had the idea to use coroplast (corrugated plastic sign board) to cover the dinged-up panels, and create a good look for an ice cream boat. Those panels varied in price everywhere I checked, but I knew I needed to get it from a sign shop, so I wouldn't have to pay the shipping on the 4' x 8' sheets. The lowest I found was $20 a sheet, so I bought 3. White was the only color I found available. One of the sign shops directed me to a vinyl supplier in town. There, I ordered a big roll of red 3" tape to create the stripes ($20). I also bought a few feet of 6 other beautiful colors of vinyl (adhesive, and 2' tall, priced by the foot, about $2 per foot). So.... all the colorful décor was done very cheaply, about $100.
My sister works as a cell tower engineer and advised me that standard 3M Scotch dbl-sided foam tape holds up phenomenally outdoors.... they use it on the job. I went a step further and bought the Exterior grade of that tape, and it is holding up great in the saltwater and harsh wind... I used it to apply the very-lightweight striped panels.
I cut strips of the colored vinyl to cover PVC pipes to make the flagpoles (they now have flags on them).
I still plan to do some upholstery of some of the benches we removed, and we'll stick those on at times, when we are pleasure-cruising. (Surprisingly, when we take it out during the week, we only see a few boats, and none have asked for ice cream. On weekends, we're selling and stopped constantly.)
My carpet tip might be helpful to some of you...even tho I'm sure y'all are much handier than I! Our carpet was okay on the inside. But the front end (where the fishing seats were) was shredded. We pulled it all off, and installed a new "carpet"... an outdoor rug from Walmart, $70. I cut it with a razor knife to fit, and poked it under the metal band with a putty knife. Then stapled like crazy with stainless steel staples.
We have waves wash across the "bow" every time we go out, and the carpet looks great still. If it just holds up for this summer, we're fine... but it appears it may last a while. The addition of that carpet made an unbelievable improvement. The boat went from looking shabby to adorable, I swear.

We opted not to re-install the fishing seats, after temporarily sticking some 'real' chairs on it, because the real chairs were so much more comfy. So we bought red and white ones to match. I realize this may be a bit "low-rent" for some people, but they sure are comfy. We secured them with one heavy-duty zip-tie, and that has worked fine.
The entry gate with "Riviera Cruiser" has now been covered with a panel with our logo, custom-cut out of vinyl for $10. I cannot believe how cheaply we were able to get a great new look for our boat. And we are now total pontoon-fans. My son even suggested we buy a 2nd one, that we decorate for pleasure-cruising only. But then we'd have a battle of me wanting it pink & green and him wanting it camo. ha
We scoured the internet for fun pontoon re-dos like this, and didn't see nearly as many as we expected. They are such perfect boats for customizing... such fun. And so perfect for an ice cream boat, with so much room.
The boat is getting rave reviews and is a big hit. We are going to do a press release, but a local newspaper contacted us before we got it out. So we were featured in it this week. If you want to see more, we are on Facebook at The Ice Cream Float, on Instagram at theicecreamfloat, and at http://www.IceCreamFloatBoat.com.