Old thread, but I will put my 2 cents worth in, especially since I have the benefit of data from this past season. I wouldn't worry too much about what other operators charge other than as a guideline for what the market will bear.
"Undercutting" as I see it is charging less than market value to get customers and taking a less than optimal profit for your services. That practice rarely ever yields positive results, it harms the other operators and sets a price point for you that you will never overcome with the customers you discount to. Nobody wins. Now if you set your pricing at a place that gives you the revenue to operate sucessfully and it is lower than the other operators, then that is not undercutting. It is filling a market void. Maybe you can do it because you go slower and burn less fuel, or offer less valued added services. But you will pick up divers who are price sensitive and willing to take less for a lower price.
My father was in retail sales, and always said "Your sale customers are just as important as your full price customers because they help you clear the inventory the full price customers wouldn't buy." Great advice. I sometimes discount on Mondays and Tuesdays, they are my most difficult days to sell.
My per seat pricing is 20% higher than the bigger operations in my market. I stayed booked solid every weekend all season, and I am booked until the very last weekend which is end of November. My boat is smaller and has less amenities but my value add is that I offer custom services. I have built a reputation for being accomodating and getting people to the sites they want to dive. I have weeded out the newer, less experienced "resort" divers and cater to advanced, seasoned NC divers. I am thinking about going up another 10% next season. I only want the customers that are willing to pay up not to have to dive on a crew boat. I don't get any push back about what I charge, although I am sure some steer away from my higher prices. But until I start seeing my bookings fall, I am going to ask for as much as I can, because that is what the market will bear. Same goes with my tank rentals and fills. I am 25% higher than the other fill options in town, but I take the tanks from the boat and bring them back in the morning. My customers are welcome to haul their tanks off to save $5 on a fill if they want to.
In a nutshell, my point is that underpricing your competition as a strategy is not wise. Find what the market will bear for the services you offer and compare that to what it costs you to operate and that is where you should set your pricing.