But in the marine world, a telltale is a good thing. It provides proof that a system is working.
Outboard motors typically direct a tiny part of their cooling water to a port where the discharge stream is made visible - so that you know that the cooling water system is functioning. (The only outboard we have here on Eolian is the little 2 HP Evinrude on our dinghy, and it does not have such a port - it doesn't have a cooling water pump either, depending instead on ram-effect for cooling water propulsion.)
But on Eolian our main engine does have a (perhaps inadvertent) telltale - when the engine is operating, some of the discharged cooling water comes out the anti-siphon vent on the port side. Inspecting the vent discharge is not more convenient than looking over the stern for water discharge in the exhaust, but I have heard that some boats direct the vent stream into a cockpit drain, thus providing easily seen proof of cooling water flow for the helmsman. And occasionally wet feet.
new pump, it is not possible to hear the pump running (yea!), so this becomes particularly important. Now, our galley saltwater foot pump draws its water from the line between the refrigerator cooling pump to the refrigerator. Thus, when the pump runs, enough pressure is produced that a stream of water makes it thru the foot pump and shows up in the sink. (Of course, this affects the logistics of washing dishes a little - you want to do the wash in this side of the sink, and the drain-for-dry in the other side.) And the frequent flow means that the water in the foot pump and lines does not get stagnant and smelly - operating the foot pump always produces fresh, clean seawater.
So if you can, replace that negative connotation with a positive one. Let the word "telltale" leave you with an impression of sitting in front of a fire with someone who is telling you a story - a story that ends saying, "all is well."