Step 1: Understanding the Concept:
The ISSCFV is a classification system developed by the FAO to standardize international statistical reporting on fishing fleet capacities.
Step 2: Detailed Explanation:
The simplified classification of fishing vessels under this scheme categorizes vessels primarily by the type of fishing gear they utilize (e.g., trawlers, purse seiners, gillnetters, longliners).
This reflects the direct relationship between vessel deck layout, auxiliary machinery, and the specific gear operated onboard.
Step 3: Final Answer:
Therefore, the simplified ISSCFV classification is based on the type of gear used.