These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Freddy Maughtai (One of Captain Phil's deckmen up to season 7) is pretty hardcore. He's known to eat the intestines of fish and even once covered his face in the blood of a fish for good luck.
He topped himself on the July 23, 2013 episode: the Wizard came up to a floating walrus carcass and wanted to drag it aboard to cut off its tusks for the ivory (which meant a few thousand dollars of extra money). But they couldn't get a line secured around the thing to lift it up. So Freddy strips down to his boxer shorts and jumps in the freezing Bering Sea in order to help properly secure the line! Captain Keith Colburn probably said it best with these two quotes:
Keith:(after the incident) Freddy Maughtai's wired differently than pretty much anybody I've ever met in my life.
Edgar Hansen occasionally indulges in this; in addition to his pyromania (including the flaming hook ritual) and biting the head off a cod, at one point he drank the blood of a cod, getting greenhorn Nick Totman to join in.
Dude, Not Funny!: After a greenhorn was almost pulled overboard, "Wild Bill" made a joke about getting his wallet if he had drowned. The still-shocked greenhorn didn't take it very well.
After a very good season, the Harris brothers have gotten a bit boastful. Jake Harris gets a friendly beatdown, after which he tells his father that he will be dependent on the two sons. Cue a few years later...
Another one may end up being Lenny messing with Captain Keith of the Wizard in one Season 7 episode. After Lenny gets his head driven into the sorting table by a BIG wave, Keith calls him inside and does the standard "How many fingers am I holding up?" test to make sure he's alright, and Lenny jokingly gives an incorrect answer before answering correctly. One season later (Season 8), and a greenhorn named Chris on the exact same ship has been brought in after complaining about numbness and tingling in his arm; when Keith comes in just minutes later, Chris is lying on the deck, convulsing and barely coherent (he would later need to be medevaced by the Coast Guard):
Keith: *holding up two fingers* Chris, how many fingers do you see? Chris: ...Four.
Season three ends with a happy reunion at the docks for the crew of the Northwestern and their families and the camera, for the final moments of the episode, linger on Jake Anderson meeting and hugging his dad. A couple of seasons later, Jake's dad is brutally murdered and his body is not found for nearly 18 months. 18 months in which Jake has to endure the nightmare of not having closure, let alone the fact that the police had no clue as to who murdered his father.
Season two saw the addition of of bearded captains Phil Harris (who had a blink and miss cameo in season one) and Captain Jonathan Hillstrand to the cast is seen as this, in terms of the show becoming more interesting with their presence.
For the Northwestern, the addition of Jake Anderson to the crew can be seen as such, as the father/son relationship between Sig and Jake provided a hook towards viewers watching the Hansen siblings.
Harsher in Hindsight: Mike Fourtner's (of the Time Bandit) reaction to one of his last interactions with Justin Tennyson. At the end of the 2011 opilio season, Mike and Justin got into a verbal sparring match on deck (partly due to lack of sleep, partly due to a wake-up firecracker from Andy Hillstrand going off near Justin putting him in a less-than-hospitable mood), which culminates in Fourtner shouting "We've got a crybaby on deck!" in reference to Justin. Two days after the season ended, Tennyson died of sleep apnea. During one of the specials filmed after Justin's death, that fight was discussed with Fourtner; the first words he said in response to the footage:
Be thankful for the fact that TVs don't yet come with Smell-O-Vision.
Cameramen and greenhorns' reaction to rough seas.
The Northwestern's tradition of biting the head off a fish for good luck.
Some of Freddie Maughatai's Samoan customs can induce this, such as a season 7 episode where he cut open a cod & drank some of its blood, smearing the rest all over his face. He even invited some of the other Wizard deckhands to join in.
Some injuries (what they show of them, at least) are this. The X-ray of the crewman who accidentally caught his hand in a grinder and needed to be evacuated by the Coast Guard by helicopter stands out - his index and middle fingers are both going sideways after the first knuckle.
Ramblin' Rose captain Elliot Neese is quickly becoming one, with some fairly rabid Hatedom, what with the trainwreck involving his personal life.
He began to be Rescued from the Scrappy Heap in Season 9, due to his generally competent handling and ownership of his new boat, the Saga — and also due to Junior now outdoing him in the Jerkass department. He might be starting to backslide in opilio season, though.
Jake Harris counts too, especially compared to his older and much more level-headed brother Josh. His own drug issues are starting to rival Elliot's personal troubles for sheer train-wreck status, although by contrast they largely happen offscreen.