I can help. best contact would be the designer
Alan Warwick of Warwick Yacht Design in Auckland
NZ. The construction is as follows; Garboards 26mm solid GRP, topsides 8mm solid GRP, deck 8mm solid GRP , cabin
sides and top 6mm balsa core
( I believe) The hull deck is joined by a solid flange through which is bolted an alloy toerail. Spindrift was launched in February 1997. I have had no hull or deck issues. The yacht is an excellent cruising and ocean going yacht with a very easy motion. She sails
well to windward and generally performs well at all points of sail. trust this helps. John/ Spindrift.