Locksmith is probably simplest, but if it’s a Mobella latch then you can also try googling the 3 digit code on one of the existing keys for a replacement.
Funny story … we went thru quite a few of the flimsy plastic locks on our 2900 so I had a pile of keys and one day I tried a few on my friends boats. About half of them worked so I gave them away as spares. Apparently there aren’t too many combinations in circulation.
Door Latch Keys
Linear Mode
