Cold water protection?

[boulderjohn]

20lbs?? let me ask you this if I use 25lbs with a 7mm 2 piece would it be better to be a little heavier? Cost is more my issue with a dry suit.

Could you repeat this question in more detail? I am nost sure I know what you are asking.

 

[String]

the people who have and do tell me that they can be pretty comfortable in 50 degree water.

You see quite a few wetsuit evangelists claiming how lovely and warm they were and they're actually shaking while talking to you. It does amuse me sometimes seeing that. A lot of people will blindly defend their kit no matter what.

Their dives have to be shorter, and most tellingly, they rarely do a second dive. It is most difficult to remain warm on the surface between dives, especially in low air temperatures (like our high 30's/low 40's which is typical for winter).

Thats the telling one here. They do dive 1 of the day and often skip dive 2 (and 3 if available). On multiday trips they sometimes skip days. They get about 50% of the dives that drysuit divers have. Air temperature here is cold in winter and in summer, there just isnt any way to warm up between them especially on RIBs.

 

[seaducer]

They also have less bouyancy issues because the neoprene compresses so much. A 7mm farmer john suit can lose as much as 20 pounds of bouyancy at depth. I don't dive dry, I know they have extra weight considerations as well, but not like wet suits do.

20lbs?? let me ask you this if I use 25lbs with a 7mm 2 piece would it be better to be a little heavier? Cost is more my issue with a dry suit.

No, you should do a proper bouyancy/weight check and be as close as possible. Just be aware that as you descend you are going to accelerate down if you do not compensate with your bcd, and conversely, you need to pay attention as you ascend. The deeper you go the more pronounced this is.

 

[LarryHinDC]

20lbs?? let me ask you this if I use 25lbs with a 7mm 2 piece would it be better to be a little heavier? Cost is more my issue with a dry suit.

If I understand your question, NO. If your suit loses 20 lbs of buoyancy, that means you will be that much heavier at depth, and adding extra weight makes it that much worse.

 

[themagni]

Have a Henderson 7m wetsuit and will be diving alot in cold water will that offer the protection a dry suit will with hood and gloves? Whats the tempature differances and comfort being cold that is, are they that big of a diffrance?

You'll want a drysuit. I already posted about my last wetsuit dive.

I use Henderson Gold Core gloves and hood. I've considered getting the dry gloves after many of my dives because my hands get cold. If that's anything to go by, then even the best wetsuit material can't compete with even the crappiest drysuit.

My last dive was in 36F water on New Year's Day. (I followed it up with a Polar Bear swim at a nearby fresh water lake. That swim was even colder (the other half of the lake was frozen solid) and I was in just swim trunks!) I wear a neoprene drysuit. Normally I wear just a pair of spandex tights and a dry-fit shirt underneath. For the polar bear dive, I wore fleece pants / shirt as well. I was warm enough, considering the leaks. (I lost a lost of weight over the last six months and so my neck seal doesn't do a very good job.)

This is for ocean shore dives in a fairly mild area. (Record temperatures are -18C -> +37C)

 

[MEDICJOJO]

Sorry... You said "A FJ can lose as much as 20lbs of bouyancy at depth". If I use 25lbs now to get under in a 7mm 2 piece and have netural bouyancy at the surface. are you saying I'm actually becoming lighter under the water and would need more weight? I have trouble with bouyancy as it is " Told it takes time and continued pratice" which I believe but the loss of 20lbs has me confused. Sorry bear with me New Diver and was woundering about this and one of those questions I wish I would of had a thought of to ask my instructor before the end of the course.

 

[seaducer]

Thats the telling one here. They do dive 1 of the day and often skip dive 2 (and 3 if available). On multiday trips they sometimes skip days. They get about 50% of the dives that drysuit divers have. Air temperature here is cold in winter and in summer, there just isnt any way to warm up between them especially on RIBs.

My local diving here in winter is limited in time and frequency by the tides, so I don't miss out on dives, or have to end my dives early. I get cold, but not dangerously so. Also the inlets are running 25 feet so the bouyancy is not much of challenge for me either. All this has simply enabled me to stay wet longer than I would have if I lived near Puget Sound, or in the UK, for example.

 

[don Francisco]

Sorry... You said "A FJ can lose as much as 20lbs of bouyancy at depth". If I use 25lbs now to get under in a 7mm 2 piece and have netural bouyancy at the surface. are you saying I'm actually becoming lighter under the water and would need more weight? I have trouble with bouyancy as it is " Told it takes time and continued pratice" which I believe but the loss of 20lbs has me confused. Sorry bear with me New Diver and was woundering about this and one of those questions I wish I would of had a thought of to ask my instructor before the end of the course.

No you're reading that backwards. Wetsuits compress and therefore reduce your displacement (bouyancy), making you heavier in the water. This means more air (not more weight) is needed at depth to offset the net weight gain.

 

[MEDICJOJO]

If I understand your question, NO. If your suit loses 20 lbs of buoyancy, that means you will be that much heavier at depth, and adding extra weight makes it that much worse.

Gotch... Thanks I'm all ass backwards so acutally I would be heavier got you now.

 

[seaducer]

Sorry... You said "A FJ can lose as much as 20lbs of bouyancy at depth". If I use 25lbs now to get under in a 7mm 2 piece and have netural bouyancy at the surface. are you saying I'm actually becoming lighter under the water and would need more weight? I have trouble with bouyancy as it is " Told it takes time and continued pratice" which I believe but the loss of 20lbs has me confused. Sorry bear with me New Diver and was woundering about this and one of those questions I wish I would of had a thought of to ask my instructor before the end of the course.

No, you compensate for bouyancy by using wieght. Exposure suits, like the 7mm we are talking about, are very bouyant on the surface. You only add what you need to sink the suit and stay nuetral in the shallows with an empty tank.

When you lose bouyancy because of wetsuit compression, you sink faster.

Let me explain it to you this way. Roll your suit up in a ball and tie a string to hold it together. Now add lead until it just starts to sink. It takes, for arguements sake 20 pounds to get to this point.

Now, dive down to, say 65 feet. You will need to remove weight to keep the suit sinking at the same rate. Maybe now you only have 5 pounds to hold the suit level.

When diving, you will compensate for the reduced bouyancy at depth by adding air to your bcd. You need to be aware that the suit will fluff out again as you ascend, because you are lowering the atmospheric pressure on the suit as you rise in the water column. So the extra air in your BCD at depth will need to be released.

You should always try to weight yourself to be nuetral, at the surface, with a near empty tank.

You will need to add air at depth for the loss of bouyancy, not lead.

Hope this helps...