It would take an inflatable kayak/canoe or a folding frame and skin rig (expensive) to combine the seaworthiness, cargo room and packability you need. I have a packraft, I absolutely wouldn't want to load a bike, even a folding one and cross Indian Arm. They are really slow, impossible in wind, single chamber and very puncturable.
You can access trail-heads from Deep Cove, Granite Falls, (whatever it's called where Elsay Creek comes in), and a few more. Get a fast boat you can paddle from PM and skip the bike?
A good, tough, bigger inflatable 2 person kayak (tight fit, tiny cargo for two people, roomy with huge cargo for solo use,) will go very nicely in a bike trailer, a full size bike and trailer would be an awkward load to stow and would still stick up a lot with some stability and aerodynamic impairment but still perfectly safe and comfortable if you know your boat, yourself and water in general. A folding bike and some folding ability to the trailer would be a big bonus. Often the bike would stay locked at the launch. That rig would work, and work well. You could find the pieces today off Craigslist, $2000-ish for good stuff that'll last for many years absent abuse. I have an Innova Helios 2 that is starting to look pretty worn after 12 years with plenty of trips, never put my bike in/on it but wouldn't hesitate to do so.
The available wheels on all kayak carts I've seen are insufficient for bike speeds/range/need not to tip over easily. A hardshell kayak as a trailer is feasible, would work great on land, but requires custom cart and bike attachment. Much worse to attach a bike to a hardshell.
Last edited by alexcanuck; 07-12-2016 at 09:21 AM.
Reason: Additional paragraph.