I have a jar which is made of 3mm thick glass and a water tight seal. How far down do you think it would go before it starts to leak?
The seal is a rubber band type thing with a toggle latch which clamps the lid down.
That type of seal isn't particularly good against pressure. It's intended for creating a vapor seal in conditions of little pressure differential. I would expect it to leak beginning at 6 ft/ 2 m of water, or about 1/5 atmosphere.
There are much better designed gaskets which improve their seal as the pressure increases. O-rings are generally incorporated into these designs, including a way to trap the O-ring.
Nelson Easy Seal Stainless Steel Exhaust Sealing Clamp Band for 3" pipe New, MBRP 5ACS Stainless 5 Inch Acu-Seal Band Clamp 1 Inch width, MBRP 5ACS Stainless 5 Inch Acu-Seal Band Clamp 1 Inch width, Diamond Eye BC225A 2 1/4" Torca In. Accu Seal In. Band Clamp, Diamond Eye BC300A 3" Torca In. Accu Seal In. Band Clamp, Diamond Eye BC200A 2" Torca In. Accu Seal In. Band Clamp, Diamond Eye BC350A 3 1/2" Torca In. Accu Seal In. Band Clamp, Diamond Eye BC400S Accue Seal 4" Stainless Steel Band Clamp 1" X 4", Diamond Eye BC500A 5" Torca Accu Seal Band Clamp Aluminized, Diamond Eye BC400A 4" Torca In.Accu Seal In. Band Clamp Aluminized, Diamond Eye BC250A 2 1/2" Torca In. Accu Seal In. Band Clamp, Diamond Eye BC250A 2 1/2" Torca In. Accu Seal In. Band Clamp, Diamond Eye BC500A 5" Torca Accu Seal Band Clamp Aluminized, Diamond Eye BC350A 3 1/2" Torca In. Accu Seal In. Band Clamp, Diamond Eye BC300A 3" Torca In. Accu Seal In. Band Clamp, Diamond Eye BC400A 4" Torca In.Accu Seal In. Band Clamp Aluminized, Diamond Eye BC200A 2" Torca In. Accu Seal In. Band Clamp, Diamond Eye BC400S Accue Seal 4" Stainless Steel Band Clamp 1" X 4", Diamond Eye BC225A 2 1/4" Torca In. Accu Seal In. Band Clamp, HOOVER/CANDY washing machine door seal retaining clamp/strap/band/clip., 5" BAND SEAL CLAMP EXHAUST MUFFLER STAINLESS STEEL, 4" BAND SEAL CLAMP EXHAUST MUFFLER STAINLESS STEEL, Breeze Hose Clamp 1/2 Band Hex Head Screw Stainless Steel 10 Clamps Per Box , Breeze Hose Clamp 1/2 Band Hex Head Screw Stainless Steel 10 Clamps Per Box , Breeze Hose Clamp 1/2 Band Hex Head Screw Stainless Steel 10 Clamps Per Box , Breeze Hose Clamp 1/2 Band Hex Head Screw Stainless Steel 10 Clamps Per Box , Breeze Hose Clamp 1/2 Band Hex Head Screw Stainless Steel 10 Clamps Per Box , Breeze Hose Clamp 1/2 Band Hex Head Screw Stainless Steel 10 Clamps Per Box , Breeze Hose Clamp 1/2 Band Hex Head Screw Stainless Steel 10 Clamps Per Box , Breeze Hose Clamp 1/2 Band Hex Head Screw Stainless Steel 10 Clamps Per Box , Breeze Hose Clamp 1/2 Band Hex Head Screw Stainless Steel 10 Clamps Per Box , Breeze Hose Clamp 1/2 Band Hex Head Screw Stainless Steel 10 Clamps Per Box , NEW DONALDSON SEAL CLAMP SEALCLAMP STAINLESS STEEL EXHAUST FLAT BAND, Murray Gold Seal No. 16 Stainless Band Screw Clamps 3/4" to 1-1/2" Set of 3, BAND-IT M21199 SCRU-SEAL CLAMPS & BAND-IT BANDS STAINLESS NEW BOX OF 10 PCS., 3" Napa Easy Seal Exhaust Band Clamp, Band Clamp Exhaust 2.25" Stainless Steel Custom Seal 2.25" OD clamping Strap, Band Clamp Exhaust 2" Stainless Steel New Custom Seal, 10 x 2.25" band strap clamp stainless seal EBC225 NEW, 10 x 2" band strap clamp stainless custom seal EBC200, 10 x 2" band strap clamp stainless custom seal 10pcs, 10 x 2.25" band strap clamp stainless custom seal 10pcs, Stainless Steel Band Clamp, EASY SEAL EXHAUST BAND CLAMP 3 1/2" W X 8" L SS USA, EASY SEAL EXHAUST BAND CLAMP 4" W X 12" L SS USA, Band Clamp 4 Inch Exhaust, 3 Inch wide, Band Clamp 2.25 Inch Exhaust, 3 Inch wide, Band Clamp 3 Inch Exhaust, 3 Inch wide, 2.25" band strap clamp universal stainless custom seal, 5" Torca "Accu Seal" Band Clamp Diesel Exhaust,