This suggestion is to utilize more of the empty space of the map. Currently 25% of the map is empty water, with a few spots for placing floating residences.

Also currently there is code available for some ocean gathering such as the fish resource.

Next, the available space of ocean is infinite as it can be expanded easily enough.

So this is a tiered suggestion:

1) easier mining in the form of
*pearl beds, oyster farms, sea shells
*the rewards could be made into fertilizer buffs (oyster shells), types of food, or jewelry which cashes into gold coins
2)medium effort coding for further offshore resources like
*kelp beds, tuna schools, scallops, abalone etc

Alternatively, the lvl 2 medium effort coding could involve a dock with X number of merchant ships with Y upgrade lvls. We could click on the ocean resource, and watch our ship speed out there to harvest the resource, then sail back to the dock after Z hours with the reward.

Eventually, if the 2nd idea was coded, you could add the 3rd lvl
3) sea adventures or monsters off the coast of our island which we can visualize
*you'd load up a general to the dock, and then launch the general to the monster--such as a band of scrag sea trolls, a kraken, or a group of pirates. This would be like a scenario battle with a much smaller map.
*sea adventures could spawn randomly or with event triggers or with a new "telescope" or "lighthouse" which finds them when activated