A compressed flat spring diaphragm showing the folds in the latex dome
High-vac diaphragm play: Returning readers will remember that I’ve written about the advantages of wearing a flat spring latex diaphragm (better heat transfer characteristics and it’s nearly impossible to under-thrust) for dive-sex and about the amazing feeling that I’ll call ‘cervical grip’ when wearing it with the dome under significant vacuum while diving or in a hyperbaric chamber under positive pressure. You can get a somewhat similar effect with a silicone (Ortho or Milex) diaphragm, but because a silicone dome is thicker and less elastic the amount of stretch to be had with a latex dome is far superior and the voids left unfilled by a silicone dome can cause painful squeeze.
In my experience as a cervical barrier fitter less than half the women correctly fitted with diaphragms have the vaginal wall structure that will allow developing and retaining a very strong vacuum in the dome. Diaphragms for the rest will work perfectly well for vanilla sex when spermicide is used in the dome, but their rugae – the transverse ridges that allow the vagina to stretch during childbirth - will not allow the rim to seal tight enough to sustain a high vacuum. A woman having a pronounced post-pubic vault and soft thick rugae is an ideal candidate to wear a latex diaphragm and achieve a high vacuum in the dome to enjoy its cervical grip even without penetrative sex. I thought high-vacuum diaphragms would be of primary interest to the young rich Europeans at The Lorelei, but it turns out that a few menopausal guests, whose rugae are atrophied, find their diaphragms often seal very well, and love them as much as reproductive age women. The older ones seem to like the clandestine masturbatory aspects of wearing a ‘fisting’ diaphragm (more about them below) w/o the mess of being mounted by a man regardless of how magnificent his body. With the availability of multi-bed hyperbaric chambers small groups of friends in this amazingly erotic fetish can all insert and establish the vacuum in their diaphragms before they go hunting men or just clubbing.
High-vac ‘Fisting’: It’s not nearly the experience of having a partner’s fist in your vagina, but still there is a lot to enjoy. With a strong vacuum in a latex dome the membrane will be stretched down over the cervix filling all the voids in both posterior and anterior fornix. In a properly fitted diaphragm the rim never fully opens because it is gripped by the muscles in the vaginal walls and the flat spring rim will not fold at a right angle to the plane of the rim so it provides a stable base to take the strain of the stretched latex w/o deforming. The folds (shown in the photo accompanying this entry) will be stretched out to fill the anterior fornix and flatten the rugae on the anterior wall causing the dome to be stretched upward putting pressure on the bladder as though the woman is being fisted by her diaphragm. So empting the bladder prior to inserting a diaphragm for high-vac play is very important. Under vacuum the dome also puts pressure on the woman’s G-spot causing some of us to become aroused and far more easily taken to orgasm by inserted fingers, vibrator or a thrusting penis. The problem with using a latex diaphragm for high-vacuum applications is that the dome failure rate is quite high for diaphragms in use for more than six months.
Latex fatigue dome failures: In high-vac dome-fisting applications the domes of properly cared for latex diaphragms will rarely tear, but will develop a thin spot or spots which will fail during use and in some cases no thin spots can be seen when checked just prior to failure. What we recommend for escorts and individual clients using latex diaphragms for high-vac applications is that regardless of how structurally sound a latex diaphragm appears to be during a stretch test no latex diaphragm should be used for high-vac play for longer than six months.
Women who enjoy high-vac diaphragm play usually use another method for contraception, typically hormonal; the pill, patch or shot, but some few have IUDs inserted or are menopausal. Since a silicone gel is used in the dome to reduce the likelihood of rugae squeeze the lube also reduces the possibility of the IUD strings sticking to the diaphragm and being pulled out when the diaphragm is removed. I of course wear an Oves cap under my fisting diaphragm. With a flat spring under high-vac I can compress the rim with my muscles and caress my G-spot in a solo orgasm so intense it’s addictive.
Establishing dome vacuum: This discussion assumes the woman has been tested and found to have the necessary pelvic anatomy to retain a significant dome vacuum at ambient atmospheric pressure. The woman should be on another effective method of contraception if a sexual encounter is anticipated in case there is a dome failure. She should also take a decongestant an hour ahead of her chamber appointment if she is prone to ear and sinus pressure equalization problems when diving or cycling in a hyperbaric chamber.
The flat spring latex diaphragm is checked for obvious signs of latex fatigue. If none are found silicone gel (we use DiveGel+ which includes a spermicide) is applied in the dome to lubricate the cervix and prevent rugae squeeze, then the diaphragm is inserted and checked to ensure the cervix is under the dome. Then the client goes into the chamber with an attendant and the pressure is increased by the desired amount
Over time we have found that a pressure of two atmospheres (the equivalent of a dive to approximately 30 feet), which puts a vacuum of about -14 psi in the dome, is sufficient to cause the dome of a Reflexions diaphragm to be sucked into all the voids on the anterior wall and surrounding the cervix. This can take a few minutes depending on how well the client adjusts to the pressure cycle and if the vacuum holds when the chamber is returned to ambient pressure. It’s a weird feeling having the vacuum push on the bladder and grip the cervix and it can take a bit of getting used to even by fisting diaphragm fetishists. Once the client’s diaphragm is under vacuum and she is comfortable she is free to leave the chamber to continue her day.
Exclusivity: High-vac dome play had, until recently, been limited to dive-sex, or a very few airline cabin attendants who could insert their diaphragms while still at altitude, but with the availability of multi-bed hyperbaric chambers at Adolph’s club, Splash, his resort/spa, The Lorelei, and another at his deep dive training facility the ability of guests to walk around during daily spa or shopping activity while enjoying the tight cervical grip of a latex diaphragm is available to those women with the necessary pelvic anatomy and money to afford it. In addition to pelvic anatomy the number of possible high-vac users is limited further because many women can’t stand the continuous pressure, the ‘cervical grip’, of the dome. It just freaks a lot of women out to have continuous pressure on their cervix. So with the small number of women, who are actually aroused by the feel of their cervix gripped by a fisting diaphragm under vacuum as a prelude to sex, the circle of women interested in the fetish is quite small and they often form close and lasting friendships.
Side effects/problems: Of course with latex diaphragms they can’t be used by couples either of whom have or develop a latex allergy, but aside from that: As mentioned earlier the dome under vacuum puts pressure on the bladder and cause the need to urinate frequently so we recommend that women prepping for a high-vac experience avoid diuretics, such as coffee.
We are finding that prolonged continuous use of a latex diaphragm under high-vac can lead to exhaustion, vaginal muscle soreness and the possibility of tears in the rugae if not lubricated with a silicone gel. Another problem can be releasing the vacuum in the dome when the wearer wants to remove her diaphragm. The hard flat spring rim has been pulled tightly against and seemingly buried in the soft tissue of the rugae making the rim very difficult to get a finger under to break the seal and fingernails can easily tear rugae. What works well as a removal aid is a flat handle ice tea spoon. The spoon can be warmed and the tip of the handle lubricated and inserted carefully under the anterior rim just behind the pubic bone. It’s not as difficult as it sounds and it just takes a time or two to develop a removal technique that works for you.
Like wearing negative rise shoes to stretch the achilles tendons after spending hours in pointe-shoes, the use of Ben Wa balls for toning before and after wearing a diaphragm at fisting vacuum is highly recommended as the vacuum can stretch the wearer’s muscles and if not countered with toning exercises may result in reduced vaginal grip.
High-vac and death rubber: I find it especially erotic to wear a latex diaphragm that I’ve harvested from the body of a woman who died while having sex. Returning readers will recall that any rubber apparel or devices I harvest for my own use I call ‘death rubber’. When we found that the life of a frequently used fisting diaphragm was only six months I was concerned that I wouldn’t be able to harvest enough FS latex diaphragms in my size to keep me supplied. However, because there is a high turnover of Towel-Girls at Splash and because many of them are tall show-girls moonlighting there a very high percentage of them wear my size diaphragm for fetish encounters. So far enough of them have run into difficulties – usually during exotic off-prem encounters - that there has been no shortage of death rubber. Fisting diaphragms are a niche market, but since the demand for latex flat spring diaphragms is increasing - from young escorts offering fetish encounters - I think with the usual casualty rate in that line of work I should have a steady supply for my personal needs.
