The connector loss would be so small as to be hardly measurable, quite likely much less than 0.2 or even 0.1db That means if it were an audible signal you'd be unable to detect any differences at all, even with a few connectors added.
Try to not to get globs of solder onto the male PL259 center pin outside, as that enlarges the diameter which could then physically distort the mating SO239 socket. That one has flexible tines or sides to grip the pin securely. Besides, solder is a poor RF conductor, unlike the often silver plated connector surfaces. ( it's a vanity thing with RF, superficial and surface mostly )
The AIS runs around 162 MHz or general marine VHF frequency channels and it seems you are talking about a very short cable run anyway. Long cable runs would introduce more loss than a few added connectors, especially as frequency goes up.
At 500Mhz you might notice a little loss and at 1 or 2 GHz it'll be increasing a lot which could become an issue for radar. Below 100Mhz it should only be defective or poorly made connections you should be concerned with. At HF ssb even wiring nuts are acceptable in a pinch, so you always keep at least one pair of those aboard, right?
Ivo s/v Linnupesa ( radio hamster station KI6S )