Final answer:
The correct term for the database described, which includes the transformed ENC, updates, and additional mariner data, is the System Electronic Navigational Chart, or SENC.
Step-by-step explanation:
The database resulting from (1) the transformation of the electronic navigational chart (ENC) by ECDIS for appropriate use, (2) the updates to the ENC by appropriate means, and (3) the additional data added by the mariner, is called the System Electronic Navigational Chart (SENC). The correct option is D) system electronic navigational chart. This is a critical component in modern maritime navigation, allowing mariners to navigate safely with the most updated chart information and relevant maritime data.