Late reply, solly.
My storage unit in Arkansas got burgled, everything gone, but I HAD...
A 7" aluminum pipe from onlinemetals.com as my main electronics enclosure. Actually 7-3/4" OD. 4' long.
An 8" acrylic hemisphere custom-blown by
https://plastic-domes-spheres.com/ to have 1/2" thick material at the apex. With a 1/2" flange and a 1" long sleeve with 2 machined square grooves for o-rings. I was the first custom order for ROV applications they had done, they did 2 for $150, now their minimum custom order is $250, still a bargain IMHO.
18650 lithium-ion batteries salvaged from modem battery packs + BMS's from batteryhookup.com to build my own 24vdc 114ah battery packs, inside of 6" ABS tubes with end caps, flooded with mineral oil to take high pressure.
1" PVC end caps with various FPV microcams potted in silicone with round glass fronts. 7 microcams.
A used Panasonic T75 SD camcorder from eBay ($50 used, $300 new) with 78x optical zoom, mounted on a pan/tilt gimbal inside the front dome.
All 8 cameras feeding a security-system DVR, hooked to a wired router, hooked to an ethernet-over-coax adapter. Raspberry Pi 3B/ Pixhawk controlling the ROV hooked to the router as well. RG59 coax as my tether.
A bit more info than just the hull but i wanted you to get a better picture of what I built.