What Parameter GPS_NAVFILTER for boats? 5 for Sea-Ship? Default is 8 for extemely dynamic 4G-Aircrafts

The parameter GPS_NAVFILTER in the documentations is explained a little poorly: https://ardupilot.org/rover/docs/parameters.html#gps-navfilter-navigation-filter-setting

I tried a deeper dive and found the following explanations in a russian wiki:
GPS_NAVFILTER.pdf (71.6 KB)

So I’m asking myself, if it would be useful to set that parameter to 6 or 5 e.g. for a boat?
I tested that, and in my opinion the GPS is ready in a shorter time and the position will be hold much better than with a value of 8.
But I don’t know the exact background of that parameter. Will it destroy any necessary functionality if I use 6 or 5?

So could anybody explain the background please.
And if my thinking is correct - what value makes sense for a boat?

Thanks in advance
Willy