Flybridge Wiring - c’mon, man!

Most of that birds nest is Not Post.

I see;
An updated VP wire harness.
Quasi electrical expansions.
Lots of repairs and mods.

You are correct about shrink connects but I don't see its use on new boats today.

In reality, Your birds nest looks pretty good compared to some new & old spaghetti messes I have witnessed.
Relax, it's not a rocket, it's a great ole boat.

But as long as your in there;

Fix that loose terminal wire.

Figure why a red wire was wrapped with yellow tape, then bundled with another yellow wire.
This would drive me nuts.

I'm thinking you need some ole phart to help clean up some of that.

I had my bridge wiring cleaned up/re done and same thing with my 95 Viking. No heat shrink. Maybe heat shrinks are not that much better. Ralph?

Maybe heat shrinks are not that much better.
In my opinion; it depends.

I don't want to quote ABYC or CFRs. I don't think they discuss shrink devices much anyway.
May I inject just some common sense.
Often you can match or exceed most printed specs just by thinking about your project a little before tearing in.

If it is a wet environment, use shrink connects AND still inspect often.
Great example here is bilge pumps & black water pumps. Shrink connects slows down the damaging effects of the wet location, they do not prevent any wet damage.
To many times I have witnessed green and failed shrink connects in the bilges.

Fly bridges could be the next wet location to note, before the hot & steaming engine room.
Spray, mist, rain, condensation & more is always in and around a fly bridge helm.
In the OPs picture, Shrink is not going to help those terminal strips.
BoeShield or like could help reduce the corrosion on these. Again, inspect often.
When you have room, secure the wire bundles away from these terminal strips for easier inspections and services.
Don't forget to use contact cleaner when servicing any connection and when finished; a new application of BoeShield or like over all.

Now my pet peeve;
Strain relief.
There are mostly 4 types of terminal crimps.
The cheap crimp that just smashes the wire conductor but does not capture the wires isolation.
The better crimp that smashes the wire conductor maybe a lil better and also (when installed correctly) captures the wires insulation with a correctly sized crimp.
The shrink crimp that smashes the wire conductor maybe a lil better and also (when installed correctly) captures the wires insulation with stiff glue.
The naked crimp
No plastic coating or jacket at all, just the lil metal tab/crimp that smashes the wire conductor. These also allow soldering the conductor to the crimp. I use these on installs using multiable conductors (NEMA183 wires or like), and ad shrink tube to firm it up.

I have witnessed wire fatigue and failure it the cheap crimps.
I have witnessed wire fatigue and failure it the better crimps when not installed correctly.
I don't recall ever witnessing any wire fatigue and failure when shrink crimps or shrink tubing is used.
Still, it is on a boat; inspect often.

Other than proper sizing, strain relief is a big deal for me when selecting a terminal end crimp.
Weather/wet resistance is a close third. I use shrink crimps and shrink tubing in any environment that vibrates or could be wet also.

In the OPs picture, The wires from the terminal strips, bundled up into a harness alongside does offer some strain relief but not rock solid.
Again, inspect often and sleep well.

IMHO as a 38 year veteran of the commercial marine industry, I don’t wire anything without using marine grade heat shrink terminals. The marine grade are shrink and have heat activated adhesive. I use these on my boats, vintage cars, RV - everything. They cost a few pennies more and take a minute to shrink but well worth the time.