Also looking for advice and/or a partner in May

@bohwaz Thanks, I'll try it. Until now I've been using a GARMIN GPS and I was looking for a NZ topo map for it, but maybe I'll leave my Garmin at home and carry only the phone :D

Beware that most phone gpss are of poor quality and do not work well in thick bush or deep valleys. They're getting better but unless you know yours is up to the sensitivity / accuracy of your garmin, think twice before leaving the gps behind. That said i'd not recommend anyone rely solely on a gps either. Paper maps, compass and know how to use them are the most reliable technology out there.

and that would also be assuming you could use your phone when its raining, which it can do for days at a time.... something they dont tend to publish on tourist sites

For Garmin maybe check out this website: http://nzopengps.org/ It seems to be using the LINZ (the official mapping govt body here) data so should be as accurate as the topo maps. But I didn't try it. As for paper and compass well you don't seem to have had a compass showing the wrong bearing after meeting some magnetic field or object or seeing your map being blown over a bluff by a wind gust. Or turning to confetti after getting wet. I find electronics to be much safer and reliable in my experience but everyone should do like she/he prefers, there is no right or wrong way :) (except going with absolutely no map/GPS/phone and no idea where you are going, and getting lost)

Phones (tablets, etc) are not a good choice for navigation. Use a GPS. The NZOpenGPS link above gives you access to the current LINZ (government) mapping data for free. However, it's searchable street maps, NOT contour maps. For Garmin contour maps, the link below takes you to the free LINZ mapset from 2013 - not the most current mapset but the best available ... and not a lot has changed. (Topo addon mapset V12.2 - click on the 'Download for PC' link) http://gwprojects.org/forum/viewtopic.php?p=24561&f=6#p24561 Instructions are provided but, essentially, the process is to download the 3 compressed files and use 7-Zip to uncompress and join together. You finish up with an img file that you copy to the GPS. A bit of mucking about but worth the effort. BTW, do you have a PLB? If not, get one. From previous posts, you are currently in Aus. Buy one and register it with AMSA. Then bring it to NZ - tramping insurance you'd be dead without.

Your high-end phone with offline map (use an app like Backcountry Navigator) runs rounds about these Garmin GPS units. At least every single one I have seen people using. What a pain. Slow slow slow. Make sure you download the latest AGPS state before you leave, and you're sweet. Put your phone in flight mode, and enable power save, and it'll work for days.

@berend if you want to start a discussion on the performance of various gps units ... feel free to start a new thread. I'm sure many of us have results of our own testing we can share with you to back up our statements made above.

My Garmin gps absolutely rocks.

Regarding sandflies in Fiordland I will never forget the harassment my tramping companion endured doing a radio sched. She opined if being driven mad by sandflies could be used as a defence for murder. We were at the head of the Mica Burn at 1100m a.s.l. From then on we did the scheds in the tent (and the cooking, out of desperation).

@Honora For sandflies, do any of the bellow help: a) Meshes (at least for the head)? Some are very light. b) DEET with say 80%? c) Impregnating the hiking clothes in advance, as one German bloke advised me in Bolivia, apparently works way better then just spraying yourself and the clothes with DEET.