Interesting Comments In My Humble Opinion! I'm agreeing with the Z man
I'm in Total agreement with the searchlight and Depth Sounder. I'm presuming that you have the right clothing for night winter work
As you are probably learning it's one of the busiest Shipping areas around and may well be the busiest leisure sailing area in Europe.
I drove a Tug around the Solent on and off for a couple of years and that experience would definitely make me go for an AIS a cheap one is listed here.
The Standard of Shipdriving in the Solent is very high and all ships either have a Pilot on board or the Masters have a Pilots exception Certificate. Whilst they may not see you the bridge will be manned and they'll most likely hear your Radio Call as they will be in contact with VTS on a regular basis. The AIS will tell you what ship you want to be talking to!
I've had the distinctly unpleasant experience of driving a tug up the North Channel at 5 knots To Soton just as Cowes Fireworks ended. So I had to put up with about 300 boats making way back to Portsmouth, Chichester and other places. Quite a few of rhem threw there spots at me and whilst it does affect your night vision it doesn't destroy it especially if you don't stare in to it, but it does get the attention of the people on the Bridge. Shining on a point in front of the bridge is a good point. It's better to have a shipdriver pissed off with you than to be ignorant of your existence. Only do this if Radio communication is not happening
Radar Reflectors are OK but there is a lot of chatter in the Solent and I wouldn't rely on a passive device.
Also when fishing/Night Moving (what a great song that was BTW) in the Solent stay tooned to The VTS ch 12 as that will give you a heads up at what shipping is around. You can also call em, tell em where you are fishing and ask em whats shaking traffic wise. Do it when there not too busy
If you are around on the water and you see an APB boat (Southampton Harbour Patrol Boats) go over to them and ask them for a copy of there leaflet and By laws for the Solent. It's a very informatibve pamphlet and written to get the leisure boater on side with the commercial element.
PLB is good but an EPIRB/SART is only good after the sh** has hit the fan it's not that good at preventing it happening
I truly hope you get as much use out of your Searider as I did my first one