"Never mind that you can go FSS and tower-to-tower pretty much all through the Hawaiian chain, or at least it used to be you could."
It's still used for multi-ship VFR flights. But regardless, HCF does great VFR flight following across the whole chain. Seamless. Nobody uses IRS anymore except military chums. And the logic was that if you were alone and had a problem, being IFR would make the rescue come much quicker
I fly inter-island in the pistons outside of work and all the coworkers think I'm absolutely nuts.
Anyone who does even a bit of overwater flight should do HUET. One of the most eye-opening experiences I've ever done. Also, the HEEDS bottle is the best thing since franks and beans... even in training, having that puppy on you reduces the fear and stress of going in 10 fold. You can buy a small "spare air" tank that Scuba divers carry for a hundred dollars and never worry again about getting snagged and running out of air, or having to leave an unconcious/trapped person in the sinking wreck because you need to surface to breathe.
Mike