CrystalLord 
Optimising for Gay
I'm responding here at the request of LightningBolt.
So, a few things:
1. I would normally define "watersports" as any Urolagnia/Urophilia. As far as I have ever heard of the term, "watersports" is just slang for urolagnia. This would include urine for any sexual pleasure. Hell, I've met people who consider holding your bladder is watersports. If you're going to define it as something besides urolagnia, fine. But you **will** confuse people (and this did confuse me heavily). The restricted definition you are going with here is not one I'm personally familiar with, and I believe will hurt your cause to label this correctly.
2. We aren't Derpi, but Derpibooru absolutely does classify some of these as watersports. Examples: [1](https://derpibooru.org/images/2391812), [2](https://derpibooru.org/images/2388903), [3](https://derpibooru.org/images/2388784), [4](https://derpibooru.org/images/2380414), [5](https://derpibooru.org/images/2367304), [6](https://derpibooru.org/images/2336692), [7](https://derpibooru.org/images/2293155). At the time of this writing, there are 1103@`wetting@` entries on derpi, and of those, 483 are also tagged @`watersports@` (43.7%). The cases that are tagged as both pretty frequently hit even the "safe" image representations you have here.
3. I personally would at least mark all of these to at_*least_* questionable. I honestly cannot imagine ever safe wetting. On Derpibooru, there's a total of 8 @`wetting && safe@` entries, and arguably I would say they also don't meet the safe criteria to me personally. That's 0.7% safe.
This isn't Derpibooru, but to me all of these would absolutely be urolagnia, and at the very least, none of these should be safe. These are all just straight up pornography to me, just with variable amounts of genitals shown in. I saw these with my SFW only filter, and immediately assumed they were a tagging mistake, and corrected them in accordance to the current rating guidelines (and the definition of watersports specified by the tag at this time).
So, a few things:
1. I would normally define "watersports" as any Urolagnia/Urophilia. As far as I have ever heard of the term, "watersports" is just slang for urolagnia. This would include urine for any sexual pleasure. Hell, I've met people who consider holding your bladder is watersports. If you're going to define it as something besides urolagnia, fine. But you **will** confuse people (and this did confuse me heavily). The restricted definition you are going with here is not one I'm personally familiar with, and I believe will hurt your cause to label this correctly.
2. We aren't Derpi, but Derpibooru absolutely does classify some of these as watersports. Examples: [1](https://derpibooru.org/images/2391812), [2](https://derpibooru.org/images/2388903), [3](https://derpibooru.org/images/2388784), [4](https://derpibooru.org/images/2380414), [5](https://derpibooru.org/images/2367304), [6](https://derpibooru.org/images/2336692), [7](https://derpibooru.org/images/2293155). At the time of this writing, there are 1103
3. I personally would at least mark all of these to at
This isn't Derpibooru, but to me all of these would absolutely be urolagnia, and at the very least, none of these should be safe. These are all just straight up pornography to me, just with variable amounts of genitals shown in. I saw these with my SFW only filter, and immediately assumed they were a tagging mistake, and corrected them in accordance to the current rating guidelines (and the definition of watersports specified by the tag at this time).