But speaking over ice tea in recently, there was no question about the seriousness Cousteau brings to any discussion of the environment.
"It still mystifies me that some people don't realize we share this planet with other creatures, and that it's not all about us," he said moments after we settled into a booth.
The South Carolina Aquarium honored this third-generation conservationist and his sister Alexandra, who is currently on expedition in the waters of the Far East for a web-based documentary, at the annual Environmental Stewardship Awards banquet last month.
Cousteau is the grandson of the iconic oceanographer Jacques-Yves Cousteau, and son and namesake of Philippe Cousteau Sr., who died tragically in 1979 while the family was on expedition in Portugal.
Phillippe Jr. and his sister, along with their mother, Jan, run EarthEcho International, an environmental nonprofit organization. Philippe is also founder of Azure Worldwide, a company that seeks to create strategic alliances to foster sustainable, eco-friendly, and eco-based development.
EarthEcho is about to expand its presence in Charleston with new educational programs that will formally be announced this summer.
Though mum on those details, Cousteau did have much to say about other topics, among them recent efforts by South Carolina to exempt the state's harbor pilots from new federal rules aimed at protecting the North Atlantic right whale, one of the world's most endangered whale species.
A new federal regulation sets a speed limit of 10 knots per hour — or roughly 11.5 mph — for boats 65 feet or longer. An average of two North Atlantic right whales are struck and killed each year, mainly by larger vessels traveling at high speeds, federal regulators contend.
But South Carolina lawmakers contend the rule unfairly disadvantages Charleston's maritime community. Port of Charleston harbor pilots use two 75-foot boats — somewhat longer than those at other ports — to steer some of the world's largest ocean-going vessels to dock.
Hoping to take advantage of a partial exemption in the rule for law enforcement vessels, the S.C. House Judiciary Committee is considering a measure placing the state's harbor boat pilots within the S.C. Naval Militia, a new agency.
"I think it's scandalous," Cousteau said. "I think it's scandalous, and I think it's criminal that people don't want to make changes to their behavior to preserve these creatures — after all, there are only 300 left."
This is why Cousteau feels it's important to play an active role in conservation and to encourage others to do the same.
"The problems we face are myriad, and as a result, it's critical to connect the dots whether it's between the community and the sea, or civic action and consumer behavior, which in turn affects corporate behavior."
More than most, Cousteau has been pursuing a multifaceted approach to promoting environmental concerns, speaking wherever he can and engaging government officials.
"Dealing with governments is tough... we're seeing a shifting tide, though," he said. "One of the things I find truly heartening is that despite the troubled economy, people are still talking about the environment. That never happened before."
Cousteau's visit to Charleston, and specifically, a stop at the Robert William Roper House on the Battery, lent another spark to the conversation, a reflection on his feelings about contemporary development.
"The Roper House ... is a wonderful example of how we used to build in harmony with nature, position our houses to include features that captured the breeze for cooling and the sunlight for light during the day. Today, we build the same house in Alaska as we do in Arizona."
Cousteau is following a philosophy very much in line with that pursued by his father and grandfather, explorers who appeared on television, wrote books, gave interviews every chance they had.
"What I do now is very much in line with their model, the cornerstone of which is the supreme importance of story and narrative," Cousteau says.
If there's a difference, it's in the various communication mediums that are essential to getting to the audience.
"You can't expect them to come to you like my grandfather could when there were only three major television networks," Cousteau says.