weather covers for electronic connectors

[gRider]

whats something good (and universal) to use for connector covers? For example, my chartplotter gets shuttled between my boat and jet ski and I want something a little better than the standard dust covers to protect the contacts. I do use a light dielectric grease, but Im looking for something similar to a balloon or whatever that is resistant to the elements to slip over the connectors.
Thanks in advance for any ideas.

[Polaris_Night]

Quick and dirty solution is a cut up piece of inner bike tube and zip ties. I use them on RF connectors all the time for waterproof temporary protection.