The Petrel Play kit comes with Sea-lect hatches.  The big advantage is that they are 100% waterproof which makes them a good idea if you roll the boat.  Personally, I think they are a bit on the ugly side and if I were to build another PP.  I would likely opt for flush hatches instead.

The problem that you will have that the base of the Sea-lect hatch is rigid and flat, and the deck of your Ch17 is radiused.  I am not sure if the base will bend enough to give you a good seal.  I would suggest that you look at flush hatches instead.  CLC sells a kit which makes them easy.

   I am at about the same point on my Chesapeake 16, when I ordered the kit and talked to a boat builder at CLC he told me that if you plan to use the boat for overnight trips the kit hatches are better than flush hatches. If you are building for looks then go with the flush hatches. If you call and are fortunate enough to get a boat builder on the other end of the phone, they love to talk about building.

Mike

   Thanks to you both for the info.  I will consider the kit hatches after all.  I worry that they might not be waterproof & I don't like to idea of all those buckles to hassle with - things that can break, etc., that's why I'm considering alternatives.

Everything about the kit hatches is robust so you need not worry about breakage.  I use my boats hard and have not had any failures.  I also find them to be quite waterproof if you take the time to properly place the weather strip over the hatch rim.  Even with waves breaking over the bow, my compartments stay dry.  If you go with the kit hatches, I have three suggestions:

    1.  When you glue up the hatch covers, make sure that they do not have any twist front to back.  It is a four hands job that I tried to do with two hands on the first boat.  I ended up with significant twist on the front hatch that required extra weather strip to get a good seal.

    2.  Take some time to get good placement of the hatch frames on back of the cover.  If you place the forward/aft frames too close to the center of the cover, it can slide forward/back and open the hatch.  You want the forward and aft frames to be close enough to the edge so that the cover can't move forward or aft.

    3.  Even though the manual does not call for it, suggest that you glass the top of the hatch covers (and the cockpit rim).  The only significant cosmetic damage that I have on my Ch17LT occurred when I got rolled in the surf.  The front hatch cover and cockpit rim (which were only covered with epoxy) were gouged up while the glassed deck survived with only light and easily repairable scratches.

As I said above, you might consider going with flush hatches.  The only draw back is that the hatch sill makes the opening about 1.5" smaller.  Installing flush hatches with the CLC kit is actually easier than making the standard Chesapeake hatches and I think they look much better.  I find them to be all but completely waterproof.  In normal paddling, the hatches stay dry but if I am in heavy rain or hit the hatch with direct stream from a hose, a little water will get in.  Here is a pict of the CLC kit installed on my wife's Frej.