Although the deck above is prettier, it is still 'incorrectly' fitted- in a deck with a joggled king plank the planks should taper so that if the deck were one continuous surface from stem to stern each plank would be full length. On top of that, having a joggled covering board on the counter is a little unusual, but to have the planks terminating in a 90deg. butt joint, rather than joggled to match the king plank and coaming covering boards is all wrong. But that's just my opinion!
In a deck laid for and aft, as Rainer is proposing, the planks can be either joggled into the covering board (traditional way) or cut to butt upto the covering board (modern way) as Rainer has drawn. I would suggest you think about installing a king plank, as well as looking more traditional it provides a wider base for fittings should you decide in the future to install a mooring bitt or similar with a wide base, having the fixings drilled through the joints would be a crime punishable by death (or similar...). I would definitely suggest you put a covering board on the forward edge of the coaming though, having seen plenty done with covering boards and without, having one finishes the deck off far better.
Of course there is another way, and one that is very rarely used these days, but would actually suit your launch very well, and that is an uncaulked taper fitted wide planked deck.
Hopefully this URL will have worked;
http://www.steamboatassociation.org.uk/ ... 003400.jpg
Greg