> what kind of heat shrink was it? The ones on the plugs/connectors were the usual ones, the one I put on the SBC was thick as I couldn’t find a thin big one,

> what kind of heat shrink was it? The ones on the plugs/connectors were the usual ones, the one I put on the SBC was thick as I couldn’t find a thin big one, and I was afraid to damage the SBC while applying the heat, so maybe it was the double layer type? But I don’t know. >how big was the waterproof enclosure? It was big enough to house the SBC (jetson Nano) and some other components needed for the UUV, not exact size but probably ~20x15cm. > better off making an aluminum plate with a raised pad that you can mount the CPU to directly and use a gasket to allow the outside of the aluminum to conduct the heat directly into the water That’s actually a really smart idea, thanks!! I did have a heatsink (those small ones fit the cpu size) but it was under that heat shrink tube so probably made things worse. > Assuming you’re not going to crazy depths We didn’t exceed 50m depth, still I was concerned the pressure might leak some water into the enclosure and this I used the heat shrink.