The nearest DIY store is Karwei:
Keizer Karellaan 2A,
7415 ZH Deventer,
0570 63 51 51
This hardware store has a very limited range of water sports equipment: lines, links, flags and the like.
From the marina, the construction market is difficult to reach by bus. The best is to borrow a bicycle.
Two other DIY stores are on the other side of the city, and are even harder to reach.