forum.heinrichsweikamp.com

Hi,


is there a comparison chart?

I'm wondering if the differences between OSTC 2, nano and + are just the physical dimensions and batteries.

As a cheaper alternative to Shearwater Perdix 2 I'm considering an OSTC sport edition for use with open system only, and like the possibility to upgrade to tec later on if needed.

/HKH

Hi,

I have our comparison sheet attached here. If you don't mind the slightly smaller display, the OSTC nano is very popular right now. Especially for CCR divers (as a backup with fixed setpoints).

Regards,
Matthias

Hi,


thank you very much for the sheet!

heinrichsweikamp wrote: 22 Mar 2026, 17:34 If you don't mind the slightly smaller display, the OSTC nano is very popular right now.

I don't see myself diving closed circuit anytime soon, only open.

I don't know about display size, I haven't had the chance to see or try any of the computers. All I know is they get good reviews.
I am leaning towards the OSTC+ due to the Qi charging and optional AA
I like the idea that I don't need to open anything up to charge it - and the idea of having AA as backup for when I forget or break the Qi.
What would happen if the USB connector got flooded on the nano?
What would happen if the AA chamber got flooded on the plus?
Any real life experience wrt. the display size? I guess the size of the nano is fine. Perhaps the size is also better on a bare arm for when visiting warm waters.


HKH

The battery compartment in the OSTC+ and the USB port in the OSTC nano are watertight. This is fine for a small leak or in freshwater, but if you dive a week-long liveaboard with a leaking battery cap or missing USB cap, both units will suffer damage.
Regards,
Matthias