Log running hours for maintenance

I have a board which I use as log for the running hours of my boat. Every time I used the boat, I write down the number of hours of the trip in a new item in this board. The required engine maintenance is based on those running hours.

Say every 50 hours, I want to set an alarm to notify me that maintenance is required. What would be the best way to do this? I tried to sum the hours of the log board into another board and create an automation based on exceedance of a certain number in another column. However, I’m not able to get the sum from the numbers from another board into an item.

Any ideas?