Seagulls are a key factor of voyages like lost shipments. The problem is, when you do that voyage at night, they're nearly invisible even with the spyglass. It gets even worse when there're clouds behind them in your line of view (clouds make it a lot harder to find seagulls even at day). It's just not fun to do these voyages, especially at night, because of how easily you can lose track of them (i've lost count of how many times i found the seagulls with my spyglass, took a few seconds to raise the sails a bit, and the seagulls were nowhere to be found again)
A simple solution would be to make the seagulls emit a very faint glow at night or when there are objects behind them through your line of view. As it is right now, it is nearly impossible to complete a lost shipment at cloudy nights without having x-ray vision.
