Yes freeboard is the height of the floe surface above the water. This obviously depends on the density of the ice and its thickness. The tricky bit is that the density of the ice is a combination of the density of the actual ice crystals and the concentrated brine trapped between them when the ice formed.
When the ice becomes warmer in the next summer this brine melts ice crystals around it and if it connects with other trapped brine it can form drainage pores which let it seep out of the ice. Ice which was visibly cleared of snow in Obuoy images becomes white and snowlike in appearance in later images because these pores as brine drains out are filled with air. the part of the ice below the water line stays soaked with water, but the salty brine is replaced by meltwater from the surface, this is the process which makes old ice less salty.
Another process which drains water from the surface are cracks and drainage channels which run over the surface to the edge of the floe.
Once the ice has become warm and porous enough (and ponds warm the ice beneath them because they let in sunlight through the reduced albedo)water in a pond can't be at a higher level than the surrounding sea water.
Some of this is based on what I have read in various places for example here
http://www.iup.uni-bremen.de/seaice/amsredata/modis/sea_ice_papers_database/ponds_in_situ_meas/Fetterer_Untersteiner_1998.pdfpart of it is based on observing photos from Obuoys etc (google image search is useful)
My comment about the freeboard in the camera2 image is based on this: To have a high freeboard the ice below the waterline must have enough buoancy to support the weight of the ice above the water. It must be thick to have a high freeboard. Cryosat uses that principle to measure ice thickness. But I would have to know the weight (density) of the stuff above the waterline to get the calculation right. E.g. if some of this stuff is snow of low density (not likely at this time of the year) or porous ice (not sure how porous this would be) it would seem thicker than it actually is, but it can't be as thin as some of the floes which barely rise above the waterline. How much thicker I don't know.