To give an additional info about Rattlesnake and Alert.
Taken from Threedecks:
Details and list of Ships built to the Alert Class design
threedecks.org
Bothe ships were built based on the same drawings by John Williams (these I showed already somewhere else, but I will show the link once more
The Rattlesnake was built in Kent, the Alert in Dover, so from different shipyards - due to this, there are slightly differences in the final dimensions (see table).
Nevertheless they were the same class (Alert-class) and very similar.
They had, which I did not know until now, two further sisterships, the HMS Pigmy, launched in 1781 and the HMS Cockatrice, launched also in 1781.
Unfortunately no drawings of these vessels are mentioned on the page of the NMM.
When you search for a specific ship, you have to know the year of launching.
F.e. when you take a look for the HMS Rattlesnake (without year), you find on wikipedia this
en.wikipedia.org
So 10 different Rattlesnake, "ours" is the 1777 version.
If you search for the Rattlesnake in Threedecks, you find one more, but keep care, several are US American vessels. You have to know, that Threedecks have ships listed only until ca. middle of the 19th century, therefore the difference
If you search after the possible ships of the HMS Alert, you find much more different vessels, launched in different years:
en.wikipedia.org
On threedecks you can find 35 ships with the name Alert, sailed in different Navies - also here a speciality of threedecks -when a ship was captured or purchased by another navy, and commissioned in the new navy, the same ship is listed new with the new name under the new nationality. With this system, the same ship can be in the list twice, or even several times, but every time for a different time period.
Hope that this info was helping and not confusing more....... Alert and Rattlesnake both launched in 1777 are the ships from the same class and very very similar