I have been using the same version of the Java runtime SDK v100.7.0 and came across the same issue. After going through their documentation at Display electronic navigational charts - ArcGIS Runtime SDK for Java under "Set ENC environment settings", it's mentioned:
ENC layers are displayed in accordance with the IHO S-52 standard. You can define the display properties of your ENC layers by using the static EncEnvironmentSettings
class. These settings apply to all ENC layers in all maps. Settings fall under three categories: mariner settings, text group visibility settings, and viewing group settings. Text group settings control the display of labels for features, mariner settings control the symbolization and presentation of ENC features, and viewing group settings allow for quickly applying settings to logical groups of feature types. Example:
// Enables display of seabed information for all ENC layers
EncEnvironmentSettings.getDisplaySettings().getTextGroupVisibilitySettings().setIsNatureOfSeabed(true);
So to alter the visibility for each of the feature type, you can call the specific category from EncEnvironmentSettings.getDisplaySettings()
and then set the visibility for a specific feature under that category using a boolean value.
This ArcGIS class documentation would help EncEnvironmentSettings.DisplaySettings Class