Spectra and cospectra of humidity, temperature, and wind fluctuations from a series of experiments at Sable Island, Nova Scotia, are sorted into three classes of stability, normalized according to Monin-Obukhov similarity theory, and compared with other published spectra from both land and water surfaces. The conditions for local isotropy are met at normalized frequencies fn≥1 in neutral and unstable conditions, and at fn≥2 in stable conditions. The downwind spectrum over water in neutral and unstable conditions is lower than over land, while in stable conditions there is no difference. The stable humidity spectrum is found to resemble the temperature spectrum. The stability dependence of humidity and thermal turbulence levels and structure functions is scaled by similarity theory. Dissipation estimates of humidity and temperature fluxes compare well with direct eddy flux measurements, while momentum fluxes are underestimated.