Alien Sea: Obviously – not all oceans are water, y’know. Just look at Ólish, or Galiné, with their golden-black hydrocarbon seas. Or the molten metal lakes on Eurymir’s day face, or the reddish salty brine of terraformed Elémíre, or the literally wine-dark seas of rusty Talentar, or the colloidal algae-gelled oceans of Pentameir, or the copper-salt-blue waters of Daliethe, or…
…and that’s before we even consider non-terrestrial planets.
Proud Merchant Race Guy: This and the next couple of tropes are difficult, because, well, it’s just not all that hatty a universe. The Imperials are notorious for their pro-commerce attitudes (see: Blue and Orange Morality) and – especially on Seranth (Imperial Core), one of the Worlds’ largest tradeworlds (see Merchant City, but if you stick to the flying cities, basically it’s like an entire planet of Wall Street/The City/Hong Kong/Singapore) you can walk along the plutarch-crowded Exchange and reasonably consider the Seranthines to be, although of multiple species, a kind of Proud Merchant Race – but even there, they need people to run the restaurants and keep the cities flying and generally provide all the other aspects of society. Of the Empire’s species, well, the eldrae plutarchs can be very mercantile without too much trouble, and the ciseflish, even more so. All the money may flow through Seranth, but an awful lot of it flows to Ólish.
There a number of other species who are known for being very mercantile – the d!grith, for example, have a much larger merchant fleet and trade volume than one might expect from the other statistics of the 22 planet D!grith Association, the codramaju are also vigorous traders even beyond the Worlds (having a speed/mass advantage in their lighthuggers, due to their innate radiation resistance), and of course, in the Rim Free Zone, absolutely everything is for sale. But it’s not like any of them don’t require enough non-merchants around to keep the hat from fitting all that tightly, either.