Wetsuit or hooded vest over 3mm

[Scubamat]

I have a 3mm full wetsuit + hood and gloves. Most of my diving is tropical, the suit seals well and doesnt flush water easily. Once water temp get below 24c it can be a little chilly. I've dived it down to 20c on a warm day in shallow water(10m) with no thermoclines and was mostly fine with a decent surface interval to warm up. After a recent trip I've decided to get some warmer for those colder dives. Should I look at 5mm or 7mm (maybe a 7/5)wetsuit or use a hooded vest with my 3mm? I'm fairly cold tolerant but don't want to waste money on a hooded vest if I should have gone for a wetsuit. Not considering real cold water diving until a dry suit is an option.

 

[stuartv]

I have 3, 5, and 7mm wetsuits and a drysuit. I kind of wish I had not bought a 7mm. I pretty much never wear it. If it's too cold for a 5mm, I go dry. The thickness of a 5 doesn't bother me. The 7mm just crosses that line into Annoyingly Thick.

 

[Diving Dubai]

I'm with @stuartv on this one.

My exposure suits are (in order of temp)

1. Lavacore/Sharkskin
2. 3mm Full
3. Combination of 3mm and Sharkskins
4. Drysuit

I do have a 5/7 and a 7mm but rarely wear them.

I did this year choose to wear my5/7 becuase the air temps were unseasonable hot (aboe 90F) but the water hadn't warmed up (72F). Unfortunately I picked up my 7mm by mistake. While I was fine in the water (if I flushed) I did set the fastest time on the surface for climbing out of a suit....

 

[Sevenrider860]

I have 3, 5, and 7mm wetsuits and a drysuit. I kind of wish I had not bought a 7mm. I pretty much never wear it. If it's too cold for a 5mm, I go dry. The thickness of a 5 doesn't bother me. The 7mm just crosses that line into Annoyingly Thick.

Stuart, I follow the same reasoning as you! I have a 3mm shorty, 3mm full, 5mm full...and then it is drysuit. I am using the Henderson Thermaxx line which I find thinner than equivalent "mm" thickness suits and suspect I have convinced myself that they provide equivalent warmth.

 

[Hoag]

I have a 3/2 full wetsuit & a vest (not hooded). I personally like this combo because when traveling it offers several options without paying too much of a penalty in terms of packing. If the water is warmer than expected, I can get by with a swimsuit & rash guard. If I get a bit chilly, I can add my vest. If that isn't quite enough, then I switch to my 3/2 wetsuit. If I need more, then I put the vest on too. If I am still cold, I take the hint and sit out a few dives to let my core temp warm up.

If I am doing a LOB in nice warm water (78-80F / 25-27C), I will typically dive with the 3/2 wetsuit during the day and add the vest if I am doing a night dive.