Pinning down this middle-aged sailor's Bond to the adventure: #2 sounds more like what I was going for: A former crew member aboard the Coral Curse who somehow survived the disease (reasons for survival to develop during story?), and who had previously been involved in a disastrously failed attempt to find and salvage the wreckage of La Gloriosa, thus having a very personal motive to repair his reputation by making another attempt.
That's a great starting point!
Remember the business card of Paladin on "Have Gun Will Travel?"
HAVE GUN WILL TRAVEL
Wire Paladin, San Francisco
In that vein, if this 'Beck' character knew the "Dead Reckoning" Seafarer's Trick, his business card (calling card?) might have said:
Ship Mage For Hire
YOU BECKON, I RECKON
Contact Beck, Nassau
Lol
Not nearly so silly: Potential Character Arcs --
(1) Discovering that all that wealth won't buy you health: Watching as Capt. Van Djik and Blackbeard grow older and feebler, and as the character starts to feel the same effects himself.
(2) The Sea Is Big and You Are Small: your vaunted "simple tricks and nonsense" are no match for the power of The Force (of nature). The beginnings of wisdom lie in realizing the extent of your own limitations.
Good things to think about! Definitely, as DM, I appreciate hearing your ideas for your PC's character arcs and development.
A post about the timeline --
From the Introduction:
Okay, that's the piece of the timeline I was forgetting. La Gloriosa definitely sank after fleeing the raid on Cartagena 15 years ago; and given that any crew member (other than cabin boy?) would have had to be at least 18 years old (?) to serve aboard her, it seems to follow that any sailor who had been aboard would now have to be at least 33 years old, and likely quite a few years more. That fits for the timeline; but forcing there to have been any survivors of the sinking raises other issues.
So, it presumably sank. So far, nobody has been found to confirm that visually. There's a lot of details that haven't been explored in the game yet - clues that are part of the trail to finding
La Gloriosa. Basically, it's a legend. There are truths, half-truths, and outright lies to fill the mystery of what happened.
For "#1" (i.e. having been directly involved with La Gloriosa): Did La Gloriosa escape pursuers long enough to reach sight of land, so survivors could row ashore, or did she sink far offshore? (I don't think we know that yet.) Was she scuttled, in order to keep important secrets (and gold) out of the hands of the pursuing French? If she was scuttled, that might have been delayed by hours until many or most people aboard her had a chance to escape to land (and to later give such conflicting interview answers about where the ship went down that the wreckage of La Gloriosa still hasn't been found). Or maybe she was scuttled because she was no longer sufficiently seaworthy (after the cannon-play and the fires) to be of further service to Spain, in the sense of braving the swells of the deep Atlantic.
Sounds like you're going with #2, so this is moot.
And furthermore -- "What the H-E-double-toothpicks, De Pointis?" Weren't France and Spain allied during Queen Anne's War? Then why was a Frenchman raiding Spanish Cartagena? Some dire villainy may have been at work.
Oops! Fifteen years before 1712 would be a raid on Cartagena in 1697, so that's before Queen Anne's War, and before Charles II favored the Bourbon dynasty to rule Spain. In 1697, Spain and France could have been at war, so the villainy might have been more political than diabolical. (But one can never tell without more facts.)
Correct, 1697 was the very tail end of the Nine Years War between French Jacobites led by Louis XIV and a European coalition (including the Spanish). It was a very tumultuous time, all these colonial powers fighting each other for scraps of the New World, only to turn around and become allies when the promise of profits outweighed their previous animosities. At least, that's how I'd describe it with my slightly jaded view.
Further timeline: the Coral Curse has now been beached for years. I'm going to reread to be sure, but it sounds as though this 'Beck' was some kind of senior member of the crew aboard the Curse. If he was 30-35 then, he could be 35-45 (or more) now, depending on how long ago the Coral Curse was beached.
Oops! again: Must add the number of months (or years?) the Curse was sitting offshore in quarantine while the various people aboard her either died of the yellow fever or recovered. . . .
I actually deliberately left vague the timeline with
The Coral Curse. That age range for 'Beck' sounds about right to me.
Edit to add: I have done some rereading of Captain Van Djik's story, and learned more about this 2nd Mate Beck: he drove the slaves whom they had rescued from the Spanish slaver ship down to the galley at gunpoint; and Van Djik clapped then in chains himself.
Well...you're reading like an engineer, looking for limitations rather than for possibilities.

No offense to engineers, my best and most brilliant friend is one.
So, yeah Van Djik ordered the slaves below at gunpoint. What exactly was Beck's role in that (if your PC = Beck)? What exactly was your PC's role in that (if your PC is different than Beck)? That's 100% up to you to decide. Maybe you dissented? Maybe you cast a charm spell?
Instead of looking for all these limits – most of which seem self-imposed rather than anything I'd actually be enforcing – I'd ask: What sort of character do I *want* to play? And how would that sort of character respond in such a situation with the slaves and Van Djik?
Er: Sorcerers and Warlocks don't automatically have proficiency with pistols or hand crossbows, though they get proficiency with light crossbows. Would a Ship Mage be proficient with pistols?
Sure! Pistol proficiency seems in keeping with the sort of character you're creating.
An officer on a naval vessel would have to obey the Captain about all matters; but on a privateer or a pirate ship, I thought the Captain ruled only in matters of combat. (Or was that during combat, which the encounter with the Acheron was?)
History texts make the distinction seem clear because the delineation between combat & everything else is clearly articulated in pirate charters. In the actual chaos of the situation...combat was imminent, Van Djik asked slaves to man the galley, Sambo the bokor refused on behalf of the slaves,
Achéron fired a lucky shot killing half the galley, combat had begun, Van Djik (who historically was very progressive regarding natives & slavery for the era, due to his own experiences aboard a slave galley) made controversial decision to have slaves chained to galley and made to row at gunpoint to replace those killed by the
Achéron. In the battle, he left other slaves on the sinking ship to drown.
The party just heard Van Djik's view of what happened. There are other views however.
In whichever case, my first inclination would be not to be Beck. Others of the crew of the Curse besides Beck and Van Djik survived the disease; and that gives a prospective character a few years to start advancing in ability and rank by developing a latent talent for magical practice. (He needn't have been 4th level while aboard her.)
OK then. Then you have a starting point for your character. Beck is an NPC. Were you the ship mage aboard
The Coral Curse?