All answers have a watery connection. Any help much appreciated :-)
9. Fishing net (5)
10. Desert counterbalanced hoist for water-lifting (7)
13. Greetings Roman (4)
15. High level Dodge car (6)
16. First element, no info lost with worker at source (7)
21. Arch enemy of Quasar in Marvel comics (9)
29. Best lake, mother! (8)
33. River meanders along a twisty line (4)
45.Those pipettes in the lab hold the solution (4,4)
46. Scuba centre, written in full (10)
62. Water jet system in organisms like the nautilus (9)
64. Lipizzaners (5,6)
66. Dry riverbed only contains water after desert rains (4)
71. Plugged in the surface of the earth or a basin (8)