He appears to have short hair that is covered with a knitted cap most of the time,
Overall, Calvin tends to be a caring, outgoing person. However, there are times where he can be hot-headed and sensitive. These flaws are evident when Calvin becomes angry with Ben’s involvement with Xander and Ben's mermaid friend secret or when Calvin found out Xander had a brief fling with his current girlfriend, Calvin grew very angry at Xander before hearing him out.
He dislikes having to keep the merpeople secret from the people, enough to actually reveal their existence to a reporter but was dismissed as "Crazy Calvin."
There are times where he disregards what risks he has. After the loss of the North Star, he took odd jobs which earned him an abundant influx of cash from high stakes poker games he attended late at night.
Xander is Calvin’s close friend and co-worker. Xander and Calvin both know of the mermaid situation going on in the town, but Calvin often argues with Ben, Xander’s best friend, on what to do about the situation surrounding the U.S. military’s involvement in Bristol Cove. Despite Calvin and Ben’s disagreements, Xander respects Calvin’s (and Ben’s) advice and takes their advice. Calvin also rooms with Xander. Calvin and Xander often confide in each other when things go awry, but their relationship becomes slightly strained when Xander reveals he hooked up with Calvin’s current girlfriend awhile back. This is shortly resolved and the two go back to being close again.
Chris is Calvin’s other close friend and co-worker. When Chris is taken by the U.S. military, Calvin and Xander go out of their way to search for him until they find him near Libbey Beach. Chris later assists Calvin by going after the mermaids on Xander’s boat, this is when Donna sings him the Siren Song. Afterwards, he decides to leave Bristol Cove to stay with his cousin in Iowa. In "Entrapment", he along with Ben, Xander, and Calvin get placed under police custody and are questioned by the FBI about Sean McClure's death, he is soon released.
Janine is Calvin’s girlfriend and turned wife throughout the show. Although Janine has only been seen several times in six of the ten episodes of the first season, Calvin reveals that he is serious about dating Janine and even asks Xander if she could move in with them. In the Season 2 finale episode "New World Order", Calvin and Janine purchase a tour boat and start a business called "Captain Calvin's Mermaid Adventure Tours" which they bring in a lot of income to begin with. In the Season 3 episode "Borders", at the Anchor Bar Calvin proposes to Janine after giving a heartfelt speech and she accepts. Janine becomes Calvin's fiance.
Later in "Life and Death", Xandar's police patrol on the water finds Calvin and Janine's tour boat disabled out in the open, Janine was celebrating her bachelorette party and one of her friends had hit their head sustaining an injury. Calvin gets reprimanded by Xander because he did not take good care of his passengers, and also because he did not purchase a new gauge to know how much gasoline they had left. Calvin explains that it isn't a problem, Xander reminds him that he is running a business now. Calvin gets a little mad because he and Xandar used to have great times on the North Star, Xander tells him that he is trying to change his life in another direction, not going back to being a fisherman. In Til Death Do Us Part, Calvin married Janine.
- As of "Distress Call", Calvin knows the truth about the existence of merpeople and allies with them, though somewhat reluctantly.
- Strangely, every time he and Janine have sex with each other, a phone always halts them.
- He refers to Levi as "Aquaman", the King of Atlantis and superhero of the Justice League, in DC comic books.