Based on my recent recent experience in the ocean environment where the tether potting is getting actual push,pull, and bend forces, I do not recommend using LocTite marine epoxy for potting, or structural attachments. It is brittle and lacks shock resistance. The potting in the tether thru connection is cracking (although not yet leaking). Because of this I ran some structural tests that indicated there is very little shear strength in an impact situation. Any attachments, such as thruster brackets, or access ports, made with this epoxy will fail if you impact a hard object in shear. For my tests, I attached a 2" ID, 2" long, PVC pipe stub to the plexiglass endplate on my ROV and left it there for several weeks, including ocean dives. When I noticed the cracking in the tether potting I tested the stub structural integrity by smacking it with a hammer (not that hard a smack, about what you would expect if your ROV did a free fall to the bottom where rocks are present). The epoxy joint instantly failed in the brittle fracture mode. There was no visible yield of the joint. Before you rely on this epoxy, I suggest you do your own testing.
Based on my personal experience, having built two wooden boats, I can recommend West Sytem G-flex epoxy. It is 1/2 the price per ounce of the Loctite, and is very well accepted in the boating community for underwater structural repair. The down side is the smallest amount you can purchase is 8 0z for 16-18 dollars. However, it is great to have around the shop for multiple uses.
Here is the marketing hype for it:
West System G-Flex Epoxy Resin
A toughened, versatile, liquid epoxy for permanent waterproof bonding of fiberglass, ceramics, metals, plastics, damp and difficult-to-bond woods. With a modulus of elasticity of 150,000 PSI, it is a bit more flexible than standard epoxies and polyester, but much stiffer than adhesive sealants. This gives G/flex the ability to make structural bonds that can absorb the stress of expansion, contraction, shock and vibration. It is ideal for bonding dissimilar materials. It can be modified with West System fillers and additives, and used to wet-out fiberglass tapes and fabrics. Mixed at a 1:1 ratio, G/flex gives you 45 minutes of working time at room temperature. It reaches an initial cure in 7 to 10 hrs and full cure in 24 hrs.
Sold in the following kits:
8 ounce kit containing 2 4 oz bottles each of epoxy and hardener
Just my opinion based on experience. Take it for what it's worth.