It’s several miles to Ship John Shoal lighthouse in the middle of the Delaware Bay. David Fisher/USGS

Michael Brownley steers a boat through a particularly foggy Delaware Bay. David Fisher/USGS

The sensor equipment at Ship John Shoal needs to be cleaned regularly to prevent fouling. The site is covered in bird droppings, a result of the lighthouse being the only solid ground for miles around. David Fisher/USGS

Sam Woomer sets up a makeshift office on the dock despite the dirty conditions. David Fisher/USGS

Sam Woomer cleans a water quality sensor at a location that is especially impacted by dirt.

Sam Woomer cleans a sensor so it can report water readings properly from Ship John Shoal lighthouse in the Delaware Bay. David Fisher/USGS

Michael Brownley works with the gage box that reports water data back to the web. David Fisher/USGS

What these photos can’t capture is the constant noise of the lighthouse horn. Every minute, it blasts out a sound that reverberates throughout your body. David Fisher/USGS

Jacob Mavrogeorge gets one last good look at the lighthouse. Thankfully, it will be at least a month before they have to venture to this place again. David Fisher/USGS

After a successful day servicing a USGS gage, technicians leave Ship John Shoal in the distance. David Fisher/USGS