Editing SEAL Delivery Vehicle (section)

===Mark 8 SDV===
The Mark 8 Mod 1 SDV is the only SDV officially in use by the US Navy and Royal Navy. It is an upgrade of the earlier Mark 8 Mod 0 SDV. The Mod 1 is quieter, faster, more efficient, and has a longer range than the Mod 0.<ref name=Klose /> Its updated electronics, materials, and battery and motor systems gives it twice the range and 1.5 times the speed of the Mod 0.<ref name=Klose>{{cite journal |last1=Klose |first1=John |title=SDV Units in Great Demand as Speed, Range Improve |journal=Seapower |date=July 2003 |url=http://www.navyleague.org/sea_power/jul_03_24.php |access-date=5 September 2018 |archive-date=6 September 2018 |archive-url=https://web.archive.org/web/20180906052703/http://www.navyleague.org/sea_power/jul_03_24.php |url-status=dead }}</ref> Another advantage of the Mark 8 Mod 1 over its predecessor is that it is built from aluminium instead of plastic reinforced fiberglass, making its hull sturdier and roomier.<ref name=Klose /> The sturdier hull means that it can be deployed from [[CH-46 Sea Knight]] and [[CH-53E Super Stallion]] helicopters, although SDVs often break or explode when dropped in the water from a helicopter, making aerial deployments impractical and undesirable.<ref name=Kelly />

The Mark 8 Mod 1 SDV has an endurance of about eight to 12 hours,<ref name=Davis /> giving it a range of {{convert|15|to|18|nmi|km|abbr=on}} with a diving team or {{convert|36|nmi|km|abbr=on}} without.<ref name="Jane's" /> The main limiting factor on endurance is not batteries or breathing gas for the SEALs, but water temperature:<ref name=Williams /> humans can only spend so much time in cold water, even with [[wetsuit]]s, before their blood pressure drops and they become dehydrated from losing blood volume and body fluids, respectively.<ref name=Kelly />
[[File:SDVmk9 SWA-Deck-Crew.jpg|thumb|left|US Navy SEALs deploy a torpedo-armed Mark 9 SDV from a submarine]]