<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"></head><body><div>Hank,</div><div>Alvin has all the O2 supply internally. Pisces has the mission O2 internally and emergency supply externally in special steel cylinders that are pressure tested to 1.25 max depth while empty.</div><div>Thanks,</div><div>Scott Waters</div><div><br></div><div><br></div><div><br></div><div id="composer_signature"><div style="font-size:85%;color:#575757" dir="auto">Sent from my U.S. Cellular® Smartphone</div></div><div><br></div><div style="font-size:100%;color:#000000"><!-- originalMessage --><div>-------- Original message --------</div><div>From: hank pronk via Personal_Submersibles <personal_submersibles@psubs.org> </div><div>Date: 7/1/17 9:59 AM (GMT-05:00) </div><div>To: Personal Submersibles General Discussion <personal_submersibles@psubs.org> </div><div>Subject: [PSUBS-MAILIST] O2 tanks </div><div><br></div></div><div style="color:#000; background-color:#fff; font-family:Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:13px"><div id="yui_3_16_0_ym19_1_1498917491013_2542">Hi all,</div><div id="yui_3_16_0_ym19_1_1498917491013_2542" dir="ltr">How do deep diving subs deal with external O2 supply. Does Alvin have external tanks for O2, are they super special tanks?</div><div id="yui_3_16_0_ym19_1_1498917491013_2542" dir="ltr">Hank</div></div></body></html>