To comment on the other measurements (temp, pressure, wind spd/dir): these are different from Hs in that Hs is by definition a statistical parameter; it is 4*st

To comment on the other measurements (temp, pressure, wind spd/dir): these are different from Hs in that Hs is by definition a statistical parameter; it is 4*stdev of the wave elevations or more practically the mean of the highest third of measured wave heights. You could have higher granularity of temperature, pressure, etc. which arguably more precisely tells you about those conditions at a given time, but a more granular time series of Hs does not necessarily define the sea state any better.