Somewhere I've read that single malts taste like "seaweed marinated in iodine".
I mostly agree... For me, it's been John Walker Black for the better part of 30 years.
Some single malts from the island of Islay may fit that description but single malts from the Speyside, Lowland and Highland regions can be fruity, sweet, honey notes, floral etc. The term Single Malt just means it's a whisky made from malted barley only, no other grain spirits are blended into it and is the product of one distillery. Johnny Walker Black is a blend which will contain malts as well as other grain whisky. The blends can and( likely does) contain whisky from several distilleries and your JWB will contain malts from Islay.
