Just got a call from Riva today about my Pet 2100 may not be warrantied from Pulse. There are different copies of instructions going around. Some say to seal and others do not say anything about sealing. I have a copy of instructions that says, "If you are using this tach in water, jetskiers, we suggest putting a bead of silicone or super glue on the seams of the front plate."
I have another copy that doesn't say anything about sealing. The tach is waterproof and/or water resistant.

Hello, I just wanted everyone to know that Pulse does recommend sealing the tach with super glue. I got a call from Riva yesterday and they told me Pulse will warranty the pet 2100. So, thank you Riva.(Mark & Pat)

Thank you for the follow-up post.