9-now the little secret.

as the fill style of this drawing is not ocean, I can move Sheet Ocean below sheet Land (easier). In case you have Ocean as the base of your initial Fill Style, no problem, Create a SHEET SEA LAKE/MARSH/POOL etc and move that sheet below Sea (original) and LAND, and work on it.

Sometimes the same thing happens when CC3 switches to SEA normal instead of SEA LAKE, as in the previous example of SYMBOLS TREES.

8 - Refresh and watch your draw gaining form

7 - Spread the Scrub items next to each other where you want your swamp/marsh to be

6 - Create SYMBOLS TREES GRASS sheet, and place it above SYMBOLS BACK sheet. Select this sheet to work with and choose Scrub icon (grass).

VERIFY if CC3 keeps the SYMBOLS TREES GRASS sheet or if it simply switches - it happens a lot to me - to the SYMBOLS TREES Sheet. In case of change, Select SYMBOLS TREES GRASS again

5 - draw some secondary rivers, note that they are in their default size (river wide), if you are more precious, adapt each one to a different size. Certainly this greater work would have resulted in a more realistic effect.