Full suit equivalent of 2.5mm shorty plus skinsuit?

[wnissen]

I realize the answer to this question varies by person, but how do those layers combine? Is that basically equivalent to a 3mm? When I put on the skinsuit (dry) I start to warm up, so it obviously contributes some insulation. I'm diving in Puerto Rico, the water temperature is 76F, which sounds incredible. My only warm-water dive was in Hawai'i at about the same temperature, in a 3mm, though I didn't write down whether that was too warm or just right. I'm good in a 7mm down to 55F, once dove that without a hood which was chilly but not unpleasant. If that's not enough exposure protection, what piece do y'all recommend I add? Thanks in advance.

 

[JackD342]

This other very recent thread covers a lot of the same ground:
What water temps can I handle with a 5mm wet suit?

When you say skinsuit, are you referring to a thin lycra/rashguard material? If so, that does not provide insulation. The warmth you feel when putting it on dry is from reducing a small amount of wind chill. Put it on wet, and you will experience the opposite, and then some. When worn under a wetsuit a lycra layer adds a little warmth by better holding a layer of water next to the body and reducing/eliminating water exchange. But not actually insulation.

 

[wnissen]

This other very recent thread covers a lot of the same ground:
What water temps can I handle with a 5mm wet suit?

When you say skinsuit, are you referring to a thin lycra/rashguard material? If so, that does not provide insulation. The warmth you feel when putting it on dry is from reducing a small amount of wind chill. Put it on wet, and you will experience the opposite, and then some. When worn under a wetsuit a lycra layer adds a little warmth by better holding a layer of water next to the body and reducing/eliminating water exchange. But not actually insulation.

Thanks, that is a helpful chart. Took me a minute as I've never seen temperature measured from the left. Looks like I'm right on the edge.

Yes, I mean an ordinary Lycra skinsuit. I'm not sure I understand the distinction here between insulation and material that reduces water exchange. Is insulation meaning something impermeable, like neoprene foam, that prevents the water from getting to your skin in the first place, versus material that slows down the exchange of water? I would still expect that both would help reduce the heat exchange. I tend to run pretty hot, but I'd really rather not have to buy a hooded vest and schlep it around if I don't have to.

 

[JackD342]

Anything that makes you warmer is of value, I just wanted to clarify the action of that lycra. You might have a double-glazed window that adds extra warmth to your home - that is an example of insulation. But if that window also is leaking around the edges, then sealing those leaks with weather stripping will add warmth, although that is not adding actual insulation. Skins, wrist and/or ankle seals, better fit, etc. all add warmth, but don't alter the heat transfer rate of the actual fabric.