I spend too much time kayaking in salt marshes or other places where mosquitos are godawful.
Deet works about 10 mins in such situations and then the mosquitos are back eating you alive.
I've switched to picaridin based bug sprays, which is not as nasty feeling, doesn't melt plastic like deet does, and is an awful lot more effective at keeping the mosquitos at bay.
You do have to spray it on your clothing, because very persistent mosquitos will swarm your clothing and try to bite you through it - and depending on the fabric and how tight it is, they can manage to bite through clothing.
Ex officio buzz off brand clothing is also good, but is basically pemerthrin soaked clothing - and you could just soak your clothing yourself if you can still buy the stuff.