Semi- Dry
- Thread starter Jrock1062
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here is the rub i live on Long Island if i want to dive more than just on vacations i will have to dive here problam is the good dives here are deep 110 - 140 down that deep it gets cold there are people here who dive that with a 7mm or a farmer john i was trying not to go dry for the cost
jrock1062,
I think you just put the last nail in the coffin of the semi-dry when you described your intended depth.
A semi-dry is basically a very high performance wetsuit. You may actually end the dive somewhat dry but the real magic is the zero flushing you get. All of your thermal protection comes from the neoprene. At the 100+ foot depths you are contemplating the neoprene will be very crushed and offer little insulating value. If you were planing lots of 30-40 foot shore diving or staying in temperate water then the semi-dry can be an alternative to going fully dry. They are pricey affairs.
Whether it is your first choice in dry suits or not a neoprene drysuit can be had for well under $1000. and that's with a modest garment that you will be able to keep lofted at 100 feet with injected air. In fact many divers use these suits with generic quality outdoor wear garments. If you make sure that the boot fits your existing fins then you're golden to be dry on the cheap.
Some of this will come down to what you are calling cold and your personal tolerance. With 0-24 dives you have no business heading to 100+ feet and 140 is in a whole other league. However there is nothing wrong with thinking ahead.
Don't burn brain cells trying to cover New York Cold water dives and Florida with the same suit. A second warm water wetsuit will let you have the right suit for the right dive for small money.
Nobody said this gear thing would be easy. Becoming gear savvy is more difficult than getting OW certified.
Pete
I think you just put the last nail in the coffin of the semi-dry when you described your intended depth.
A semi-dry is basically a very high performance wetsuit. You may actually end the dive somewhat dry but the real magic is the zero flushing you get. All of your thermal protection comes from the neoprene. At the 100+ foot depths you are contemplating the neoprene will be very crushed and offer little insulating value. If you were planing lots of 30-40 foot shore diving or staying in temperate water then the semi-dry can be an alternative to going fully dry. They are pricey affairs.
Whether it is your first choice in dry suits or not a neoprene drysuit can be had for well under $1000. and that's with a modest garment that you will be able to keep lofted at 100 feet with injected air. In fact many divers use these suits with generic quality outdoor wear garments. If you make sure that the boot fits your existing fins then you're golden to be dry on the cheap.
Some of this will come down to what you are calling cold and your personal tolerance. With 0-24 dives you have no business heading to 100+ feet and 140 is in a whole other league. However there is nothing wrong with thinking ahead.
Don't burn brain cells trying to cover New York Cold water dives and Florida with the same suit. A second warm water wetsuit will let you have the right suit for the right dive for small money.
Nobody said this gear thing would be easy. Becoming gear savvy is more difficult than getting OW certified.
Pete
How to save $1000 on a dry suit:
Total: $2500
OR, just buy dry suit. Save $1000.
All the best, James
- get a quality, off-the-rack stock size wet suit, 7mm, $450
- get cold, buy custom semi-dry wetsuit, $550
- get cold, buy drysuit, $1500
Total: $2500
OR, just buy dry suit. Save $1000.
All the best, James
As a year round Northeast diver I can assure you that you will be C-O-L-D at the depths you describe - even in the summer - if you dive semi-dry. Sure some people do it in multiple layers of wetsuits, but they get C-O-L-D.
Seim dry suits were developed in resonse to two percevieved needs:
1. A desire by dive shop owners to stock fewer sizes (to keep the overhead costs down), and
2. To better accommodate on-line sales where a diver cannot try on a suti before buying it.
The reality is that the most important factor in the performance of a wet suit is the fit. It must be form fitting enough to allow minimal leakage and it must have no voids near the joints (in particular the shoulder/armpit area) that would pump water through the suit when you move. It also must not be so tight as tp restrict circulation. In short, it has to fit well and you end up needing a lot of stock suit sizes to fit most body types.
Suit "quality" comes into the equation in terms of how stretchy the neoprene is, but that is a double edged sword as well as stretchy neoprene is often more prone to having the bubbles permanantly crunch (reducing insulation) sooner than less stretchy neoprene - so again the primary criteria should be fit. If the cheap suit fits you better, buy it, as the more expensive suit will offer you no advantage for the extra cash.
Into this world was thus born the semi-dry. The idea was simple: Put good seals on the suit and you wil be able to tolerate a less than perfect fit without excessive flushing. This then allows dealers to stock fewer sizes and allows divers a greater chance of success with on-line sales.
In practice, it is not such a hot idea.
1. A perfect fitting semi-dry is still no warmer than a perfect fitting wet suit.
2. A less than perfect fitting sem-dry is perhaps as warm as a perfect fitting wetsuit, but
3. Beyond reasonable and finite limits a void in a semi dry will still pump water past even the best seal available, and
4. In most cases, semi-dry's do not use a very sophisticated neck seal so to get good performance you have to pair it with a matching vest/hood combination to minimize water flow.
The best semi-dry I ever had (and the only one that I would say was truly semi-dry was a Comox semi-dry that incorporated a genuine rear entry across the shoulders dry suit zipper and a neoprene neck seal very similar to a dry suit seal except you did not fold it over. It was in effect a dry suit with semi-dry ankle seals rather than attached boots. The neck and ankle seals let in just enough water to avoid a squeeze and some parts (lower back, chest, etc) would actually still be dry after the dive.
Realistically if you are diving in cold water (below 50 degrees) or are diving in water below 55-60 degrees at depths below 100-130 ft, you need to get a dry suit.
The good news is that a good quality neoprene suit can be had for around $500. As indicated above, they are quite warm with minimal undergarments. I use a pair of sweat pants and a Tee shirt in mine on dives to 150 feet with bottom temps around 39-40 degrees and run times around and hour and step up to slightly warmer poly propolene fleece pants and shirt (about the same weight as sweat pants and sweat shirt) in similar temps when their is no thermocline. So equipped, I stay much warmer than I ever did with a trilam, 400g thinsulate undergarments, and dry gloves (costing 3 or 4 times as much.)
Another advantage of a neoprene dry suit is that they are stretchy and offer a much more streamlined and snugger fit than a trilam, vulcanized rubber or crushed neoprene suit with the result that they swim much like a wet suit where you do not have to be concerned about body position, air shifting, or air rushing to your feet. And they are much more comfortable as they squeeze you less and squeeze you less sharply, so you can comfortably dive with much less air in the suit.
A final advantage is that if you get a hole in a trilam, at best you have a noticeable leak and the insulation value of your undergarmets plummets in that area or at worst you have a very wet suit that does virtually nothing to keep you warm. In contrast, if you get a hole in a neoprene suit, you at best have a small damp spot and at worst have a very efficient semi-dry suit that allows you to complete the dive in reasonable comfort.
This January I have to take a cave class in Florida and will have to revert to a trilam as my neoprene drysuit would be way too warm. I am actually not looking forward to it, despite all the DUI literature bashing neoprene suits for the last 20 years.
1. A desire by dive shop owners to stock fewer sizes (to keep the overhead costs down), and
2. To better accommodate on-line sales where a diver cannot try on a suti before buying it.
The reality is that the most important factor in the performance of a wet suit is the fit. It must be form fitting enough to allow minimal leakage and it must have no voids near the joints (in particular the shoulder/armpit area) that would pump water through the suit when you move. It also must not be so tight as tp restrict circulation. In short, it has to fit well and you end up needing a lot of stock suit sizes to fit most body types.
Suit "quality" comes into the equation in terms of how stretchy the neoprene is, but that is a double edged sword as well as stretchy neoprene is often more prone to having the bubbles permanantly crunch (reducing insulation) sooner than less stretchy neoprene - so again the primary criteria should be fit. If the cheap suit fits you better, buy it, as the more expensive suit will offer you no advantage for the extra cash.
Into this world was thus born the semi-dry. The idea was simple: Put good seals on the suit and you wil be able to tolerate a less than perfect fit without excessive flushing. This then allows dealers to stock fewer sizes and allows divers a greater chance of success with on-line sales.
In practice, it is not such a hot idea.
1. A perfect fitting semi-dry is still no warmer than a perfect fitting wet suit.
2. A less than perfect fitting sem-dry is perhaps as warm as a perfect fitting wetsuit, but
3. Beyond reasonable and finite limits a void in a semi dry will still pump water past even the best seal available, and
4. In most cases, semi-dry's do not use a very sophisticated neck seal so to get good performance you have to pair it with a matching vest/hood combination to minimize water flow.
The best semi-dry I ever had (and the only one that I would say was truly semi-dry was a Comox semi-dry that incorporated a genuine rear entry across the shoulders dry suit zipper and a neoprene neck seal very similar to a dry suit seal except you did not fold it over. It was in effect a dry suit with semi-dry ankle seals rather than attached boots. The neck and ankle seals let in just enough water to avoid a squeeze and some parts (lower back, chest, etc) would actually still be dry after the dive.
Realistically if you are diving in cold water (below 50 degrees) or are diving in water below 55-60 degrees at depths below 100-130 ft, you need to get a dry suit.
The good news is that a good quality neoprene suit can be had for around $500. As indicated above, they are quite warm with minimal undergarments. I use a pair of sweat pants and a Tee shirt in mine on dives to 150 feet with bottom temps around 39-40 degrees and run times around and hour and step up to slightly warmer poly propolene fleece pants and shirt (about the same weight as sweat pants and sweat shirt) in similar temps when their is no thermocline. So equipped, I stay much warmer than I ever did with a trilam, 400g thinsulate undergarments, and dry gloves (costing 3 or 4 times as much.)
Another advantage of a neoprene dry suit is that they are stretchy and offer a much more streamlined and snugger fit than a trilam, vulcanized rubber or crushed neoprene suit with the result that they swim much like a wet suit where you do not have to be concerned about body position, air shifting, or air rushing to your feet. And they are much more comfortable as they squeeze you less and squeeze you less sharply, so you can comfortably dive with much less air in the suit.
A final advantage is that if you get a hole in a trilam, at best you have a noticeable leak and the insulation value of your undergarmets plummets in that area or at worst you have a very wet suit that does virtually nothing to keep you warm. In contrast, if you get a hole in a neoprene suit, you at best have a small damp spot and at worst have a very efficient semi-dry suit that allows you to complete the dive in reasonable comfort.
This January I have to take a cave class in Florida and will have to revert to a trilam as my neoprene drysuit would be way too warm. I am actually not looking forward to it, despite all the DUI literature bashing neoprene suits for the last 20 years.
divinginn
Contributor
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