Are these boots self draining?

Water does drain from them, but there are no gromets for that purpose.

What size Jet fin do I need, I have the HEAVY-DUTY DIVE BOOT, 6.5MM boot size 9

Most likely a LG. That said, the only way to know for sure is to visit an Authorized SCUBAPRO Dealer and try them on with the booties you are using. You can also refer to the Fin Sizing Guide, matching our different booties thicknesses with fin models. https://johnsonoutdoors.widen.net/content/lk9fu4pt2n/jpeg/SP_SizeChart_FINS_ADJ_EN_Metric.jpg

Will the size XXXL heavy duty boot fit into an XL Seawing Nova fin pocket?

Good Afternoon, The XL Seawing Nova will fit up to that size heavy duty boot. It is always best to try the boots and fins on at your local Authorized SCUBAPRO dealer to ensure a proper fit. Thank you and Happy Diving!

Heavy-Duty Dive Boot, 6.5mm, Black, 2XS

Overview

If you have ever suffered from cold feet or found yourself stumbling over sharp rocks as you made your way down to the beach, you'll appreciate the HEAVY-DUTY 6.5MM dive boot. Built to handle the tough stuff, with a reinforced toe and heel and a substantial molded rubber sole, the HEAVY-DUTY 6.5MM is both durable and comfortable, making it the ideal wetsuit boot for cold water and harsh conditions. A Diamond Span interior enhances comfort plus improves warmth.

FEATURES

Heavy-duty nylon 2-sided neoprene ensures comfort and durability.

Reinforced toe and heel defend against the elements as well as providing fin pocket abrasion resistance.

Heavy-duty rubber anti-slip molded sole shield feet from sharp rocks and craggy surfaces

Hool & loop zipper-end patch secures the side zipper when closed.

SPECS

General
Boot Type	Boot
Activity	Technical
Size	2XS
Closure	Zipper
Material	Nylon/Neoprene
Sole Type	HD Rubber Textured Sole, Reinforced Toe and Heel
UPC	4048336332019
Technical Details
Thickness	6.5 mm
Product Weight (M)	0.70307 kg