Hello! It's been awhile! :D

After many years of being away, we are wading back in to the waters. I am going through my old stuff and came across my two 300 watt heaters. My problem is I cannot tell if they are submersible or not, and I cannot find info on the internet. They are Aquanest model A264 300 watt heaters. I feel like a dunce when it comes to searching for this information. So, if you can assist me I would greatly appreciate it.