The leash rule stands...
Absolutely, although Rocky has learned a new trick -- and, after 64 years, taught my wife a new skill. She has never been good about closing things tight -- dresser drawers, bifold doors, etc., and she seldom checked to see if a door striker "clicked" shut. Because I'm fussy about such things, I like to think that she's not careless about shutting things completely, but is showing her love for me by deliberately leaving things for me to do.
But, Rocky has learned that he can "test" a door by shoving it -- and has "escaped" more than once. We currently live in a smaller, slower neighborhood of a larger city, and all our neighbors know Rocky from their frequent, leashed walks. Without exception, we get a call within a couple of minutes, usually before Betsy even knows he's gone, "We have Rocky..."
So, after all these years, the new dog has taught the old one (although Betsy's not a dog -- she gets better looking as she gets older) the new trick of making sure the door is latched.
But, back to the pond -- the first thing we did, within days of buying the property, was to have field fence installed around the entire perimeter. We didn't stop at our 5 acres; we had my daughter's adjacent 2.5 acres re-fenced at the same time. Now, the entire 7.5 acre compound is secure for all the dogs and my granddaughters. The greys could probably jump the fence if they were determined, but it's not in their natures -- I think a piece of string would serve as a sufficient fence -- the 4' high field fence stops them cold, and the 7.5 acres gives them plenty of room without the temptation of the outside world.
As you know, while greyhounds love to run. it's not something they do all the time. Our guys are content with maybe 5 minutes of joyful gamboling, then it's back to being couch potatoes. Our vet calls them "statues".
You're also absolutely correct about them being the best pets. We had gone through several disastrous dogs, to the point where I had sworn we'd never have another, before Betsy brought Grandy home 6 years ago. Now, we have two.
Grandy is timid and shy and it's hard to get a picture of her, but here's a shot of Rocky as the intrepid explorer.