Difference between surface and marine RX's
 

Okay here's the issue I traded in my SCT boot's for a pair of boats, as I did this I expected to use my DX3R radio and bought a MR3000 RX. after installing it I realized that they (dx3r) wont bind to the marine RX. So what is the difference between they sr3100 and MR3000. Can I not use the SR radio in the boats? They seem kinda water tight not 100%

If you have marine logo on the back of transmitter, along with DSM2 and surface logos, you can bind and use marine receiver MR3000.