Helmet over Hood? (cold water wreck)

[Schwob]

I have some (bump) helmet questions.
I played with a construction hard hat and found it (at least the one I played with) unusable for me. By time I have it adjusted to fit, the front sits low enough that I cannot get a mask to fit properly. Seems like the back of my head (where the little wheel adjustment is) is not playing along - or it's just the helmet I tried - but as just a construction hardhat it would work fine.
Maybe I get more purchase by trying to put the adjustable plastic webbing into a BMX helmet or such after taking the foam out... (like Andy Davis suggests on his website) but at that point I might also just consider buying a helmet.

Either way, what do those of you do that dive wrecks (and / or caves) in cold (and really cold) and warm water and prefer to use a bump helmet?
When in cold water do you use the helmet over the hood?
Even over a thick hood?
If so, how well does that fit (brand of helmet)?
And for you, does the same helmet then (re-adjusted) also fit you w/o hood?
No issues with mask fit in either case?
(I mean for cold water that's three things on top of each other sort of: hood, mask, helmet...)

P.S.:
I found two threads on SB on helmets in recent years, but have not come across an answer to my "wonderings".

 

[JMBL]

Sometimes, I use this helmet (English comment at the bottom of the page) while cave diving, over a thick hood (water is an average 12°C around here), no problem to fit my diving mask while wearing it. Tried it for spelunking once or twice, so without a hood, no problem. Hope, it helps.

https://www.amazon.fr/Petzl-Ecrin-Roc/dp/B006U3PKYM

 

[fish149]

I have a toddler sized bike helmet with the foam ripped out. Got it for $10 on eBay. Works great with or without.

 

[Schwob]

Sometimes, I use this helmet (English comment at the bottom of the page) while cave diving, over a thick hood (water is an average 12°C around here), no problem to fit my diving mask while wearing it. Tried it for spelunking once or twice, so without a hood, no problem. Hope, it helps.

https://www.amazon.fr/Petzl-Ecrin-Roc/dp/B006U3PKYM

Yeah, if I find one that might help. I am hoping to find an actually impact rated helmet w/o foam. Not that an impact rating would be needed just for diving, but it would be multi use... Anyway finding new, un-used suspension mount no-foam climbing helmets... I may be strange, but I hesitate buying such a helmet used, not knowing where it's been and what it was exposed too... will keep looking so.

 

[Schwob]

I have a toddler sized bike helmet with the foam ripped out. Got it for $10 on eBay. Works great with or without.

Just strapping it on your head with the foam out or adding a suspension of sorts?
For diving with a hood a suspensin is likely really not necessary ... but it still has to fit that way... worth a look so...

 

[-JD-]

NESS has a couple types ...
Light Monkey Cave Diving Helmet - Blue
Aqua Lung Bump Helmet

The LM one specifically talks about a removable suspension for use over thick hoods.

 

[fish149]

Just strapping it on your head with the foam out or adding a suspension of sorts?
For diving with a hood a suspensin is likely really not necessary ... but it still has to fit that way... worth a look so...

I lined it with some strips of sponge, about 1/2 inch thick. That's just enough to keep it evenly spaced around my head.

 

[Schwob]

@fish149 , @-JD- , @JMBL :
Thanks!

 

[king_of_battle]

THIS has worked for me. Mine is in orange (which I don't see on amazon right now) which complements my drysuit. They are knockoffs of the petzl vertex vent. Fits me with a hood on.

 

[covediver]

Some research divers working around sea lion rookeries in Alaska have taken to wear climber's helmets as a precaution against "mouthing."