style="font-variant:small-caps;">HI</span> ]{}disc (Paper III) and stellar disc (Paper IV). The series is based on a large part of the PhD thesis of the first author [@Peters2014]. The paper has the following outline. In Section \[sec:hydrostaticmodels\], we will provide a detailed description of hydrostatic models we use and detail the fitting strategy. Section \[sec:hydrostaticresults\] presents and discusses the results. We summarise the results in Section \[sec:hydrostaticssummary\]

Modelling Strategy {#sec:hydrostaticmodels}
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Overall Strategy & Sample
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@Celnik1979A proposed a new strategy in which the flaring of the [ <span style="font-variant:small-caps;">HI</span> ]{} layers is used as a tracer of the vertical gravitational potential in the Galaxy. This method was extended to edge-on galaxy NGC891 by @vdk81c. In combination with a traditional rotation curve decomposition, this offers a view on both the radial and vertical directions of the gravitational potential. The dark matter halo model can be fit to this. Further previous work on this subject, using the flaring of gas layers, includes that by @Olling1995A [@Olling1996A], @Olling2000, @bc97, @nsj05, @k03, @kdkh07 and @bj08, and others.

We will use this same strategy to model the dark matter halo shape for the sample of eight galaxies defined in Paper I and extensively studied in further 