I'll throw in a couple of ideas and words I have on this topic as it's always something I've been intrigued with.
Cindy and I take these type of tours all the time, and anything over $50 per person would need to be guaranteed to offer spectacular photos and probably some photo guidence from a fellow photographer. Or be billed as a photo specific tour where you're not competeing with too many other photographers on the boat.
For instance, a 3 hour sunset tour on Pictured Rocks Lakeshore in Michigan on a big, double decker boat that gets us right up in some of the caves was only $35 per person. Granted, there were 40-50 people on this boat, but they know everyone is out to get good shots, so they pay close attention to the real scenic areas and offer plenty of time for you to get your shot. Drinks were offered for sale, and you had the option to be outside on the deck, inside in a Heated/Air Conditioned cabin depending on the weather and the seats were typical vinyl covered bench seats. There was a guide that spoke over a loud speaker type PA System to let you know what you were looking at and the history of the shoreline
A 4 hour swamp tour in Louisiana that got us within feet of dozens of gators, birds, turtles and the operator even reached in and grabbed a baby gator to allow us to hold and take pictures was $30 per person. Tour offered cold drinks and you sat in a comfy chair up off the bottom of the aluminum boat. I think this boat held 16 people and if he knew you were there to get good photography, he made sure you got your shot before he moved on. No top on the boat, but you were in and out of cypress trees so there was some shade at times. But you were at the mercy of Mother Nature. The tour guide knew his stuff and never stopped talking about what we were seeing and could answer every question anyone on the boat asked.
A one hour Air-Boat ride in Okeechobee Florida we just took was $25 per person. Wasnt billed as a photo tour and offered no drinks or food, but did get us close to some gators. Seating was out in the open on a vinyl bench seat and our cameras were getting splashed most of the time from the spray off the front of the boat. Boat probably held 10 people and he could care less if you got the shot, but would slow down when gators were in the water for a minute or so. No top, so you were exposed to the elements the whole tour and it was pretty warm. The guide did talk about things on the shoreline at various areas, but nothing that wasnt too obvious. For instance, he points out a orange tree and says "Folks, that a Florida Orange tree right there. Behind it you'll see a grapefruit tree."
4 hour whale watching tour in Baja that was a life time goal cost $55 per person. Included a sandwhich, cold drink and the chance to photograph dozens of migrating Gray Whales and pet a few that would come right up under the boat. You were basically just sitting on a moulded fiberglass bench in a small 25' panga and had a guide that spoke no English to offer photo guidence or tutorial on what we were seeing. But it was still one of the coolest boat tours we've been on just for the experience of being that close to such an huge animal. There were probably ten other people on the boat with you to compete with while trying to get a picture in a moving boat in open ocean.
Our favorite one was a boat tour off La Paz in Baja which took you out to the Isla Espititu Santo which is a huge island off the coast of Southern Baja. Tour took about 4 hours total, and had an English speaking local guide who had a great sence of humor which made the tour even better. They were very knowledgable about the flora, fauna and ecology we were seeing, and would go out of their way to get you in close to get a shot you wanted.
They anchored off this one section where hundreds of Sea Lions had taken over a small piece of rock and we were offered snorkeling gear and allowed to jump in and swim with the sea lions!
This was the most expensive of the tours we've taken and was around $85 per person. But they brought the boat up to a secluded beautiful section of beach where they grilled lunch (Fish Tacos) and had cold drinks available at all times on the boat. When ever they saw me lift up the camera to get a shot, they slowed the boat and would ask if I got what I was trying too before they would take back off.
These were small 25' to 30' boats with a covered canopy and you sat on vinyl benches that lined the edges of the boat. There were maybe 15-20 people total on the boat.
So what I'm trying to let you know is if you were to charge anything over the $100 price range, you'd have to be offering some good options. Supplied lunches or meals depending on the amount of time the tour is, choice of drinks, limited people on the boat or even a one on one experience with maybe just the people in your party. Guidence for photographers who might need it and a boat that made an all day tour be plenty comfortable.
Another item you need to think about is making sure your boat and gear is in top notch condition. It's one thing to be out cruising with friends and have something go wrong, but have a paying customer on board and things could go down the drian very quick (Pun Intended
) Just mentioning this because we were looking into doing some guided tours for the RV/Photography crowd to some of the places we've visited that arent too well known.
Once we started looking into the hassles of insurance, proper equipment to make sure everyone has a memorable time and all the other things that go along with running a top notch tour company, it sort of took the fun out of the whole adventure thing. Radio to get ahold of help incase the need arises, gear to get you out if anything bad should happen, a back up boat or motor incase one fails when you have tours planned and items like that are all items you need to bring to the top of the list and can add up in price very quickly. Dont even get me started with the hassles of marketing your tour company and the advertising costs that will follow! That is a entirely different topic, but one that needs to be thought about before you get going.
Hope this info helps, and if you get it going, make sure to let us know. We travel through Florida from time to time and love a good day out on the water.