This Advertisement is for the Mask with TWO SHORT SIGHT CORRECTIVE LENSES. We will fit the lenses for you prior to dispatch. The lenses you require should be selected from the drop down lists below. Lenses are in stock and we will be able to dispatch your mask within hours of purchase! Lens come in 0.50 increments starting at -1.0 ending with -6.0. If you have a need for SPH Correction greater than -6.0 please consider the Beaver Discovery Mask that we sell via this Web Site.

Featuring Tempered Glass and a Super Easy Fit Liquid Silicone Skirt the SEAC SUB Extreme Mask has been a World Best Seller for many years. It is so popular that you hardly ever fail to see several scuba divers on every dive boat trusting their vision to this comfortable mask! It is also perfect for snorkelling.

The Extreme Mask has really low internal volume mask and is very easy to clear - you’ll probably fail to get any water inside in any event - that’s why the Extreme is so popular. This mask is especially easy to adjust - you simply push in a little button on the side to loosen the mask straps tension.

The Extreme is quite a compact mask and may not be suitable for especially large / wide faces. This is one of the most reliable and comfortable dive masks we offer. Most men, woman and youths will easily achieve an excellent seal, but if you have a very wide face or especially prominent nose please consider the Tigullio Devil & Beaver Discovery Corrective Masks we offer. The Extreme mask is supplied inside a protective clear Perspex box and is not supplied with a plastic mask box.

Short Sightedness Correction - Your prescription probably has 3 entries for each eye. The first two of these are the relevant entries for your Corrective Mask Lenses. These are the SPH and the CYL. If the CYL entry is less than 0.75 it is best to ignore it. If the CYL is greater than +1.00 it can be taken into account so that your lenses are a closer match to your prescription.

• CYL = Less than +1.0
• Take your SPH and deduct 0.25 (allows for in water magnification).
• Have in mind that our lenses come in 0.50 increments.
• Then round the result to the next lower 0.50.
• Example 1. SPH from Prescription is -2.75, thus we deduct 0.25 and the result is -2.50. Thus a Corrective Lens with a SPH of -2.50 should be ordered.
• Example 2. SPH from Prescription is -3.50, thus we deduct 0.25 and the result is -3.25. A Corrective lens of SPH is not available as they come in 0.50 Increments so in this example the lens to order should be rounded downwards to SPH -3.00.

• CYL = More than 1.0
• Add one half of your CYL Correction to the SPH from your prescription then round down the result.
• Example 1. SPH from your Prescription is -4.00 and CYL from Prescription is 2.00. Take half the CYL Correction, this is 1.00,  and add this to your SPH Correction equals -5.00. Then deduct 0.25 to allow for natural in water magnification equals -4.75. You would need order a corrective lens of -4.50 as they come in 0.50 increments.

Corrective Lenses for Long Sightedness are not available for this Mask.  Optx 2020 Stick on Half Moon Shaped Lenses can be purchased as a separate item to create bifocal correction for gauge reading etc. Optx 2020 Lenses fit all the masks we sell.

• Normal Price for each Lens is £30.
  
• £59.95 for one SEAC Extreme Mask fitted with 2 Correction Lenses
• UK's Lowest Price