As a former US Marine in reconnaissance, I have become VERY good at land navigation.
What tips can you give to help with the corrections you'd need to allow for from wind and currents? Shooting for a place off to the side of a target and then "turning left" or "turning right" at the shore is a good way, but how do you know how much to allow for. Currents can be more predictable then wind.
What are your tips and tricks?
Steve, I believe your experience in land navigation will be of better use for SEA KAYAKING than any marine (as in nautical, not your branch of service) navigation skills.
As others have pointed out above, you will likely be either following a coast (hand railing) where you will be checking off nav points as you go - often referred to as piloting - or you will probably be doing a limited distance between islands, using the ded reckoning techniques of direction/distance.
Obviously this is your concern in poor vis, where direction/time/speed calcs are compromised by an unknown cross-track error. Unlike land nav where Naismith's Rule can be applied (after enough experience to determine individual corrections), on the sea you are dealing with a guesstimate on the effects of wind and usually an unknown tidal stream/current effect.
There is little that can be done at a practical level beyond "aiming off".
I once paddled around Holy Island, North Wales, an area famous for its tide races. Due to these races, and the fact that the British Admiralty has long been surveying the waters of the world, these is very accurate information about the timing/strength of lateral sea movement around the island.
I was using a GPS to log the trip (I couldn't get lost as long as I kept the terrain to my right) and I was interested to note my speed changing on what seemed like a flat sea. Later I worked out that I was hitting eddies-within-eddies, while there was no evidence or information that I could have adapted to or planned for.
When I have been paddling in wind on a transit (US terminology = range) and watching the compass, my bearing/course made good variation is usually between 10 and 20 degrees. This of course doesn't take into account wind strength/direction, my speed, tide etc, but it's just an observation.
As an experiment, one mirror calm night I went for a paddle in very thick fog with no compass (It WAS deliberate!). I was paddling a route I have done hundreds of times, from a headland to an island, a distance of 1000 metres.
I set off and counted my paddle strokes. After one hundred double strokes I heard waves gently breaking on rocks to my right and I was surprised at my speed
, assuming I had hit the island exactly where I was aiming. As the land appeared, at a range of about 10 metres, I discovered I was EXACTLY where I had left from!
100 paddle strokes and I had done a 180 degrees turn, despite trying very hard to maintain direction.
Planning and experience is very useful, but the honest will admit that luck plays a big part.
And, these days, GPS!