Is this a physical lifting, or water penetrating the bond between the hull & deck? I had some water penetrating about a 12" section on the port side about 2 feet back from the shroud. I used a sealer that injected in the seam as a liquid and cured flexible to correct the problem. There was evidence the previous owner may have had boat damage repaired there, so I don't think it was a factory issue. My hull was built at Pearson Composites.
G'day down under! 2002 would be an early hull number.
It should be a number stamped in the transom gelcoat upper starboard side.
Hull number format:
XXX19###YYYY where XXX19 = Manufacturer Model J/109, ### = Hull number, YYYY = Date code
J Boats Europe: FRJBE19189I405 = Hull number: 189
Pearson Composites: PCX19266H506 = Hull number: 266
Tilliston Pearson: TSP19076D303 = Hull number: 76
While ours is still intact I have repaired the hull to deck joint on other boats before. If the deck is noticeably lifted I would consult a pro to look at it before applying any adhesives as you may want to back up the repair from the inside with strips of glass tape/tabbing seeing that the hull to deck joint is an important component. They may want to glue the seam and then clamp the joint using a ratchet strap or equivalent before fiberglass taping the inside seam.
If it is just leaking with no visual deformation of the deck; Plexus (uv stabilized), Six-10, G-flex, or even 3M 5200 can be used for the repair of the seam itself. Plexus and Six-10 have convenient mixing tips for this type of application. Use high quality tape to mask all nearby areas and remove it while material is still tacky. For preparing the seam I used a diamond blade on a Fein Multimaster tool, the type of blade used for cutting tile grout as it is far more accurate and safer than a small grinding wheel with less risk of damaging the surrounding area. In my last application I used a sharp mixing stick to trim away all excess along the tape line so as to keep all new material below the surface grade. This left me room for a thin gel coat line and a perfect color match.
Your issue interested me in general since I have seen ice collect in the hull to deck joint groove during the winter along with mildew in the summer. I have been thinking of using something to prevent water from collecting in there similar to Sika 295 UV by making a very small fillet to delete the gap. The concern is less about the summer mildew and more about the ice working to create cracks in our cold outdoor winter storage. Depending on where you store your boat, ice could have been the original trigger for the issue you are currently experiencing.
Good luck, Todd