LAUSR

We thank Regnard and others for their thorough appreciation of our article on the circulatory effects of increased hydrostatic pressure due to immersion (Weenink and Wingelaar, 2021) as we are convinced that scientific progress can only be made through the exchange of thoughts (Regnard et al., 2022). It is interesting to note the amount of criticism they subject our statements to. Many of the differences in insight between their group and ours may be reduced to semantics or other trivial factors. We will therefore not counter every detail of the commentary as this would be more suitable for a pro and con manuscript—which we would be more than willing to partake in. Our two groups, however, do seem to have quite opposing views when it comes to the most fundamental issue of our article, i.e., whether hydrostatic pressure is able to exert a compressing force on the vasculature. We strongly believe it cannot and believe the analogy with the hyperbaric chamber perfectly serves to explain this. In our opinion, Regnard et al. too easily dismiss this analogy, thereby disregarding important information that supports our viewpoint. First and foremost, we would like to stress that in our comparison between wet compression (immersion) and dry compression (in a hyperbaric chamber), we disregard the effects of a vertical pressure gradient. Most certainly, as Regnard et al. point out, this vertical pressure gradient is virtually zero during dry compression, while the pressure increase during vertical immersion in water is 1 cm H2O per cm of immersion by definition. However, the point we are making is that hydrostatic pressure, independent of its magnitude or whether it is caused by dry or wet compression, does not selectively squeeze the vascular wall. Pressure is transmitted throughout all tissues (which are indeed OPEN ACCESS