The oceanObs API is an OGC API - Features service and follows this standard as documented here: http://docs.opengeospatial.org/is/17-069r3/17-069r3.html.
Data is returned in a FeatureCollection object that describes the returned data set. Data points are found in the features field which contains a number of Feature objects as described below.
Feature objects are wrapped in a GeoJSON FeatureCollection, which includes:
Links to pages;
Generic fields for every Feature
Internal database ID
Always equal to "Feature"
This is a GeoJSON feature and the table below describes the returned data:
Parameter ID identifying the parameter by a name
Station ID identifying the station
Timestamp of create time in observation database in RFC3339 5.6 format
Observation time in RFC3339 5.6 format