i dive deep to 40m just wearing a rashguard and tights. Not a problem but of coz u cant stay that long at that depth with normal air.
It depend on the thermocline. Though i already know a remedy to keep me warm before a dive.
Eat something that could heat up the body temperature. Like eggs, soya bean, ginger or milk.
I often do that before night dives.

i dive deep to 40m just wearing a rashguard and tights. Not a problem but of coz u cant stay that long at that depth with normal air.
It depend on the thermocline. Though i already know a remedy to keep me warm before a dive.
Eat something that could heat up the body temperature. Like eggs, soya bean, ginger or milk.
I often do that before night dives.

Thanks for the tips... i like to take teh o panas before every dive.. heeheh..

oldturtle do you have a DC? if u have a DC it will highlight the limit bottom time for no deco dive.
If you dont have one, dont do deep diving. It is hazardous without one.
other than that unfit, headache, nausea, fatigue are also the remedies for DCS.
err zaff and ejadboulala i am only answering for ur q on how deep can u dive without a wetsuit. Not telling u it is ok to dive 40m without any planning first
and dont try to go deep when you are not confident enough with yourself. The mind can play trick or should i say narcosis to be exactly.

Depth:40m
bottom time: 40min
No deco: 3min (this means that my no deco time left in minute before i start to deco and at the sametime i start to ascent from 40m depth)
i had around 8min to stay at that depth.I have no need for a deco stops.
Work my way up to 15m to have more flexible no-deco time.