They paid tens of thousands to have software made for this purpose. It sucked and was totally unable to handle the simultaneous realtime access and modification that was required.
They knew I was good with computers, so asked me if I had any ideas. In about an hour I made them a Google Sheet that worked great for the next several years until I left.
And when you take away their sheet, you better be ready to support them. If they need to track new data, they could just add a new column in their sheet. Now they have to talk with tech. If tech blocks operations, they're quickly back to their sheets. The tool made by tech should be an enabler, not something to force compliance or whatever.
Sheets are so, so flexible. This can be really hard to replace. At the same time, they're also brittle with little system support. Like the example above, what if you assign someone not working that day to a boat? Or accidentally put two boats in the same location? Lots of small issues that proper tooling could handle, especially when backed with more data inside the system.
What made the operators happy to use my tool in the end was that they didn't have to punch so many numbers. They would copy paste numbers from various systems into their sheet every hour to keep track. The tooling pulls it in real-time.
So we replaced this one sheet, because it would help them a lot. But their other sheets we're leaving untouched for now. Nothing to gain by moving them. So judge each sheet individually.
As much as people will rely on databse (rdbms/sql) backed applicatons, in the end a lot of the business world runs on spreadsheets... Not only that, but excel, and I'm assuming plenty of others have integration points for pulling data from other resources... Spreadsheet masters can do very impressive things with what appears to be a simple tool.