A paperback book about a son writing about his father.  The father
was a light bulb salesman in the New York City area and a avid
fisherman.  The father was kind of a "Death of a Salesman" character.
 The two would often go on fishing trips to Bimini or thereabouts,
fishing for bonefish.  The author wrote about
the "square groupers" that they occasionally found floating on the
water.  "Square Groupers" were the local's term for plastic wrapped bales of
marijuana which drug runners would drop from airplanes when they were
being chased by the Federales.

I believe your book is "The Last Marlin: The Story of a Father and
Son," by Fred Waitzkin.

"Fred Waitzkin recounts his experiences of growing up in a bizarrely
dysfunctional family in the America of the fifties. Stella Rosenblatt
is the New York-born daughter of an immigrant industrialist who has
built Globe Lighting into the leading company in its field. Abe
Waitzkin is a high-powered lighting salesman from Boston. Stella, a
radical artist with a strong aversion to the business world and all
its trappings,finds herself irresistibly drawn to the wily, dynamic
and ambitious young Abe. Their marriage eventually degenerates into a
clash of two enormously powerful wills, with their two sons, the
author and his younger brother Bill, caught in the middle...

In dozens of thrillingly-rendered scenes, Waitzkin lets the reader
share the joys of the sea (especially around the idyllic Bahama island
of Bimini)and the excitement of deep-sea sport fishing (for Marlin,
sailfish, tuna, giant sharks, etc.). In Waitzkin's capable hands, the
dissolution and frightening aftermath of his parents' ill-starred
marriage and the concurrent ruin of Bimini's pristine beauty are made
to mirror each other. Through it all, the author keeps on fishing,
using that activity as a superb metaphor for unfulfilled longing and
pereptually renewed hope."

Amazon: The Last Marlin: The Story of a Father and Son
http://www.amazon.com/Last-Marlin-Story-Father-Son/dp/0141001887

"Fred Waitzkin returns with another father-son memoir, 'The Last
Marlin.' This one's about his own father, their shared love of fishing
and the civil wars that have raged within the Waitzkin clan for nearly
a half-century.

'In the 50's,' Waitzkin writes, 'there was no one in New York City
landing more big fluorescent lighting jobs than my dad.' Abe Waitzkin,
a salesman for the Globe Lighting company of Brooklyn, became a legend
in the trade by selling lighting fixtures to contractors building the
postwar generation of Manhattan skyscrapers...

Waitzkin takes us back to a 1950's where fedora-wearing salesmen
closed deals with union bosses during the early rounds of title
fights; to a 60's where brilliant jazz trumpeters surrendered their
genius to bottles of booze on East 14th Street; to a 70's where Bimini
islanders fished all day for stray bales of marijuana."

New York Times: Fishing for Answers 
http://query.nytimes.com/gst/fullpage.html?res=9B0CE3DF153FF935A25757C0A9669C8B63

My Google search strategy:

Google Web Search: father salesman fishing bimini
://www.google.com/search?hl=en&q=father+salesman+fishing+bimini

I hope this is the right book! If it is not, please request
clarification; I'll be glad to offer further assistance before you
rate my answer.

Best regards,
pinkfreud