Aquaman - or, more specifically, his near career-long status as the go-to whipping boy regarding his 'powers' (and the widely-held belief in the near-total lack thereof) when compared to his fellow superheroes. It has occurred to me that the cancellation of all his prior solo comic book series is most likely actually due to one thing: wasted potential. Aquaman should, by all rights, be the most bad-assed comic book there ever was!
Consider this: In outer space, it's pitch black. It's much the same on the ocean floor - although, for some reason, the ocean backgrounds in the comics are always shown as being blue... Both environments are freezing cold. The empty vacuum of space can make things explode - while all of the pressure at the bottom of the ocean instead makes things implode. And to revisit that aforementioned term, empty - well, asides from the odd cosmic-based character, outer space is largely just that: (empty) space.
It's not like that on the bottom of the ocean, though! There, teaming and unimaginable horrors exist - literally anything that the writers and artists could possibly conceive, because a) no man-made craft can yet navigate the absolute deepest depths of the ocean; and b) any life-forms that scientists bring up from such depths perish due to the immense pressure changes. Most of these creatures have razor-sharp teeth... and each and every one of them hungers to consume you, in only the most violent manner possible!
Proponents of aquatic characters have, in the past, often cited the much bandied-about statistic that seventy-one percent of the Earth's surface is covered by the sea. However, if one were to judge solely on the basis of every previous Aquaman series (and to be sure, Marvel's Namor the Sub-Mariner suffers this same fate as well), absolutely no one would ever guess that! This is because - seemingly without fail - writers always try and awkwardly shoehorn in plots that relate to the surface world.
Quick - name all of the protectors of Gotham City... heck, even Metropolis! Then name the oceans' defenders, at present, in the DC Universe (while also bearing in mind that Garth, formerly Aquaboy, is now deceased - and so is Dolphin for that matter). Yeah... there's something of a disparity there.
In truth, Aquaman should realistically (well, insofar as any fictional account of super-humans could ever be called 'realistic') be almost entirely unconcerned about life above the waves (although an exception can of course be made for issues pertaining to the impact that surface-dweller borne pollution has had upon the Earth's overall environment). Still, perhaps the best format for further Aquaman stories ought to be eleven issues dedicated solely to his underwater adventures... with only one (likely the now-requisite annual company-wide cross-over 'event' story) taking place on dry land.
That, at any rate, is just my two cents about Aquaman.