If someone pees from a row boat in the middle of the Atlantic Ocean, how would you detect that from River Beach (a little north of Boston, Massachussets)?

When you have a working detector for that, you should be able to answer the questions yourself :-). I wish you best of luck with your project, but don't forget to count the orders of magnitude of the effects involved.

Added: Sorry, I very wrongly attibuted the projects of others to you. My intention was to encourage you to to make some orders-of-magnitude estimates of effects involved, and through this put these ideas on the back burner for the next centuries.

If someone pees from a row boat in the middle of the Atlantic Ocean, how would you detect that from River Beach (a little north of Boston, Massachussets)?

Via satellite

Let's take a long rod and bend in just to the level before breaking. And then wait till the gravitational wave arrives (or somebody pees from the row boat).

First; gravitational waves do not occur on Earth, it occurs when some two great celestial bodies (black holes, neutron stars, pulsars etc.) having great amount of mass collides.

Second; it is gravity waves (internal or external) that occur on Earth because of crustal movements and will have significant variations to the circulation and atmospheric wave patterns such as atmospheric gravity waves or surface waves on oceans.

We can detect those disturbances in the upper atmospheric parameters just like thermal, electrical properties of the actual environment before, during and after the earthquakes. Parameters include like electron or ion density, plasma critical frequency, scale height or maximum height of diurnal ionospheric layers, total electron content from sensors like vertical pulsed radars (ionosonde) or GPS receivers etc.

These parameters may change in the presence of earthquake cycles due to the disturbance from the gravity effects and may be classified as earthquake precursors as mentioned in most of the upper atmospheric or ionospheric articles and journal papers of people who try to model and have knowledge about mechanics of gravity waves and their relation with earthquakes. .

Mark Beker, Xander Campman, Jules van Oven, Wim Walk, Jack Levell, Zijian Tang, Mike Danilouchkine, Dirk Smit, Johannes van den Brand, Soumen Koley, Maria Bader; Innovations in seismic sensors driven by the search for gravitational waves. The Leading Edge ; 35 (7): 590–593. doi: https://doi.org/10.1190/tle35070590.1